How much coffee grounds do I use for a large percolator?

I am a big fan of ignoring volumetric measures and using weight instead.

Especially for a huge pot like this one, any old kitchen scale should be precise enough to allow a good dosage (for just a cup or two, you need more precision). The general recommendation for filter coffee is

  60g coffee per 1000g water

(And remember that 1000g =1kg = 1l.)

As for the "bath water territory", I admit that I have gone down to "1 heaping teaspoon per mug", which translates to ca. 7g per 200-220g or 30-35g per 1000g. That's pretty close to what aficionados call "bath water", but I'm sometimes a whimp when it comes to filter coffee.
If you are dealing with the average crowd of American (weak) coffee drinkers (sorry for bashing the cliche here), I think you can easily go down to 50g/l or even slightly below without the majority even noticing.

But as you are working with a small local roaster, I suggest you get a small sample beforehand and run a little test. Note that his coffee might (should!) brew differently from the supermarket sawdust. You might want to choose the right roast if you're going to lower the ratio. Tlk to your roaster: Factors that should be kept in mind are the type of machine and the fact that the water will probably be very hot, so the selected roast should be able to withstand it somewhat.

Also, the grind will be important, but "medium" should be a good starting point. If your machine needs coarser grounds, you will have to increase the coffee by 5-10% to get the same result.

Finally, even if you did some test runs at home and think you perfected every parameter, that kind of machine you will be using is not designed to maximize the coffee quality, but the output - that's just how it is. The results should still be significantly better than "get a few cans of [you know which brands] and boil them to death with chlorinated water". Most of your guests will enjoy the fête and the community and pay only little attention to the coffee - they will taste your effort and appreciate your dedication nevertheless.

(And if you do all that to make sure you can have a decent cup of coffee at the festival, I still think that's worth it!)


How to order Caffe Macchiato and be sure you get one?

The problem with ordering a "Macchiato" is that it's only half of the name of a traditional coffee drink.

"Macchiato" means "stained" or "flecked" and not more.

In Italy, you have either

Latte macchiato: *Milk "stained" with coffee (more precisely caffè or espresso) or
Espresso macchiato: Espresso (or caffè) "stained" with a spoonful of milk foam.

If you order a "Macciato" without qualifier, you will either get what the chain defines as such (for Starbucks, a lot of milk and foam with one or multiple shots of espresso) or what your barista thinks of first - and that would often be a (latte) macchiato, i.e. a glass of milk and foam with an espresso layer inbetween.

So my recommendation is:

If you want a serving of espresso with a bit of milk, order an espresso macchiato. I just double-checked with the Starbucks US website and yes, they do have espresso macchiato on the menu. Any decent barista from the (self proclaimed) high-end places you mention should be familiar with these terms anyway. The fine difference between "coffee" and "caffè" (see below) might be "lost in translation" and they will be using an espresso machine in 99% of all cases anyway.

Comment re. your Wikipedia link:

Please note the spelling: caffè is not the same as American coffee! The former is what you get when you use a stovetop moka pot, which creates a brew similar (but not identical) to espresso. Both are served in rather small serving units and for coffee drinks used somewhat interchangeably. Espresso shots in a bar or coffee shop, caffè often in a domestic setting (no need for fancy machinery).


This is a perfectly good idea, if you freeze the coffee as cubes and plan to use them to chill your iced coffee without watering it down.

If you plan to simply freeze the coffee for drinking later I can imagine it being a bad idea, because you will lose some of the flavor. If you even poured milk or cream into the coffee you're planning to freeze, I would even recommend less freezing it, because no kind of milk products can be safely frozen and those are always better used fresh.


Aluminum is not a very strong metal when it comes to moving parts. Probably, that small rod that keeps the handle in place is made from steel to last longer. Rust may be formed because of steam or if you don't towel dry it after washing it. No worries as it is not in contact with your beverage. I can't check mine as it's not currently with me.


How can I distinguish prepared cups of regular and decaf?

A similar question was asked on the cooking stack exchange quite a few years back. The answers and comments there mostly address your first and third points.

It seems that there's consensus that bubble formation differs between instant and brewed. However, I assume from your comment that both your decaf and regular were instant. There may still be differences in the bubbles. From Wayfaring Stranger on the Cooking SE:

  Coffee foam/bubbles is made up of a mixture of proteins, sugars, oil droplets, caffeine etc, and the lifetime of a bubble is highly dependent on the composition of its membrane. Given that decaf is coffee that's been solvent extracted, it wouldn't be at all surprising to see its different composition affecting bubble lifetime. However, no one seems to have conducted definitive studies of the matter.

There's a variety of caffeine testing strips that might be worth investing in if you're routinely serving coffee to someone who's sensitive to caffeine, but I wouldn't know how feasible it'd be to craft your own alternative with some at-home chemistry.


How can I improve this Chemex cold brew method?

What you're talking about is the "Japanese iced coffee" method, which is hot-water brew directly over ice. In contrast, cold-brew is using cold water in contact with the grounds. See techniques at other questions tagged as cold-brew.

This article from Counter Culture, also referenced in the article you linked, suggest Japanese iced as an alternative to cold brew. The articles suggest that directly brewing hot coffee over ice retains more of the volatile flavour compounds.

If you have had true cold-brew before, most methods use several times as much coffee grounds to brew as with other methods (some then dilute this with, e.g., water or milk). For example, normalized to a 200mL "cup" (~6.5 fl.oz.) of brewed coffee: Blue Bottle suggests about 3x more coffee for cold brew (45g per 200mL) than for drip (14g per 200mL). If you're coming from that strength, it's no wonder you're finding it watery.

To your first question: If you want a stronger brew, why not simply use more coffee grounds? Your amount (21g grounds to 300g water+ice is about 14g/200mL cup) is already at the higher end of the spectrum for drip coffee; the industry standard is closer to 7g per cup/dose. But if you want it stronger, use more beans!

On your other question: this temperature change shouldn't be an issue. You said you're using a Chemex (e.g., classic 3-cup) -- it is made from Pyrex brand borosilicate glass, which has very good thermal shock properties. Even a lesser glass (e.g., non-tempered soda-lime glass) shouldn't be a problem at these temperatures (slowly dripping boiling water onto ice). (However, for example, ice into glass at oven temperatures could certainly be a problem).


How can I make coffee without a machine?

Cold brew, SUPER simple version. A.K.A. my college days version.

One tbsp of any coffee per cup of water. Let it sit in the fridge for about 12 hrs. Pour and drink.

In my college days I got a half gallon milk jug. Washed it out of course. Which is about 8 cups. I would put 8 tbsp of any coffee I could get my hands on and put it in the fridge over night. No heating water, no other preparations, no shaking, nothing.

The next day I would fill my coffee mug and put 2 sugar cubes (about 40 calories BTW) or honey into the cup and microwave it to a drinkable temperature. When you get close to the bottom it will be like mud, full of coffee grinds. I would just toss that out and start the next one for the next day. I think I calculated that with the cost of the sugar cubes and coffee it was like 15 cents per cup.

Tips: the thought that more coffee will deliver more caffeine is true but I found that a ratio of more than 1.5 tbsp of coffee per cup of water can make it to bitter to enjoy. Plus I found that the time in the fridge does not have to be precise if you stick to the 1 tbsp to 1 cup plan. There were times when I left it in there for 20 hours and it was still drinkable.


My coffee pot is a 12 cup Cooks.It has a built in filter yet i still feel the need to put a regular filter in it as well.Am i just being foolish?

Totally up to you.
A paper filter will filter the oils in the coffee and give you a "brighter" flavor in your coffee. Filtering the oil out may also change the health factors of drinking coffee, since those oils provide nutrition elements that are both good for you and bad for you.
The metal filter by itself will let oils and fines into your final brew. The oils will make the coffee taste richer and more earthy. The fines (which are dust like fine grinds of coffee) will create some sludge in the final brew. Not a lot probably, but some.
I suggest that if you like how the coffee tastes with a paper filter, keep using a paper filter. And if you want to try without paper, consult the manual first to make absolutely sure this is ok with your machine. I can't tell which model Cooks 12 cup you have, so I don't know if your machine actually has a permanent filter or just a basket.


What's the minimum recommended age for drinking a coffee?

In short: there is no minimum recommended age for drinking coffee, but on the other hand it's not good idea to have kids drink coffee all day long.

It is discussed in depth in the parenting site of Stack Exchange and the top answer thee states:

  The bottom line is that caffeine is generally safe, but it does have significant effects in children as well as adults. Note that children are much more likely to encounter caffeine in a soft drink than in tea or coffee; that's what you have to worry about, I think, not Starbucks. A cup of green tea contains ~15-25 mg of caffeine, which is around the limit where there were no noteworthy affects for a 50 kg child, so if they want to hang out at a cafe, they don't even have to limit themselves to strictly caffeine-free options

Personally I'm not going to allow my children to have coffee before they are in highschool - that's the age where they can start to decide on things affecting their health.


Will I get dehydrated from drinking coffee?

Edit: I realized there have been a very similar answer on Coffee SE, already. Excuse me for my lack of attention. I add this link before my answer to complete the discussion.

Does coffee cause dehydration?

What's happening inside our bodies, is quite a question. I cannot answer that. However, I can answer the entitled question; no, you shouldn't be dehydrated by consuming coffee.

There are numerous studies made on this issue. Some of them including sports area some others are generic.

Scott Paluska states:

Caffeine is the most commonly consumed drug in the world, and athletes frequently use it as an ergogenic aid. It improves performance and endurance during prolonged, exhaustive exercise. To a lesser degree it also enhances short-term, high-intensity athletic performance. Caffeine improves concentration, reduces fatigue, and enhances alertness. Habitual intake does not diminish caffeine's ergogenic properties. Several mechanisms have been proposed to explain the physiologic effects of caffeine, but adenosine receptor antagonism most likely accounts for the primary mode of action. It is relatively safe and has no known negative performance effects, nor does it cause significant dehydration or electrolyte imbalance during exercise. Routine caffeine consumption may cause tolerance or dependence, and abrupt discontinuation produces irritability, mood shifts, headache, drowsiness, or fatigue. Major sport governing bodies ban excessive use of caffeine, but current monitoring techniques are inadequate, and ethical dilemmas persist regarding caffeine intake by athletes.

Paluska, S. A. (2003). Caffeine and exercise. Curr Sports Med Rep, 2(4), 213-9.
Yang Zhang et al. states:

In practical terms, there was no evidence that caffeine ingestion in moderation would impair fluid balance during prolonged exercise in the heat or during 3 hours of recovery.

Zhang, Y., Carter, S. J., Schumacker, R. E., Neggers, Y. H., Curtner-Smith, M. D., Richardson, M. T., ... & Bishop, P. A. (2014). Effect of caffeine ingestion on fluid balance during exercise in the heat and during recovery. South African Journal of Sports Medicine, 26(2), 43-47.
Sophie Killer et al. states:

It is often suggested that coffee causes dehydration and its consumption should be avoided or significantly reduced to maintain fluid balance. The aim of this study was to directly compare the effects of coffee consumption against water ingestion across a range of validated hydration assessment techniques. In a counterbalanced cross-over design, 50 male coffee drinkers (habitually consuming 3–6 cups per day) participated in two trials, each lasting three consecutive days. In addition to controlled physical activity, food and fluid intake, participants consumed either 4×200 mL of coffee containing 4 mg/kg caffeine (C) or water (W). Total body water (TBW) was calculated pre- and post-trial via ingestion of Deuterium Oxide. Urinary and haematological hydration markers were recorded daily in addition to nude body mass measurement (BM). Plasma was analysed for caffeine to confirm compliance. There were no significant changes in TBW from beginning to end of either trial and no differences between trials (51.5±1.4 vs. 51.4±1.3 kg, for C and W, respectively). No differences were observed between trials across any haematological markers or in 24 h urine volume (2409±660 vs. 2428±669 mL, for C and W, respectively), USG, osmolality or creatinine. Mean urinary Na+ excretion was higher in C than W (p = 0.02). No significant differences in BM were found between conditions, although a small progressive daily fall was observed within both trials (0.4±0.5 kg; p<0.05). Our data show that there were no significant differences across a wide range of haematological and urinary markers of hydration status between trials. These data suggest that coffee, when consumed in moderation by caffeine habituated males provides similar hydrating qualities to water.

Killer, S. C., Blannin, A. K., & Jeukendrup, A. E. (2014). No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PloS one, 9(1), e84154.
Adam Seal, et al. states:

The data indicate that caffeine intake of 6 mg kg−1 in the form of coffee can induce an acute diuretic effect, while 3 mg kg−1 do not disturb fluid balance in healthy casual coffee drinking adults at rest.

Seal, A. D., Bardis, C. N., Gavrieli, A., Grigorakis, P., Adams, J. D., Arnaoutis, G., ... & Kavouras, S. A. (2017). coffee with high but not low caffeine content augments Fluid and electrolyte excretion at rest. Frontiers in Nutrition, 4, 40.

The most interesting result here may be the last one as it suggests that you should avoid drinking a lot. 6 mg caffeine per kg may cause dehydration.

Actually, from this previous discussion we roughly know how much caffeine are there in a cup of coffee; around 160. This means, as a typical 80 kg male, if you don't consume 4 cups of coffee one after another, it should not be a problem. In a few hours, some of the caffeine should be metabolize so you can drink some more. But I don't know the pharmakinetics of caffeine. Maybe a pharmacologist may answer better. In which intervals should we drink the maximum amount of coffee and not to dehydrate?


A fine grind, especially an espresso grind, are usually avoided when doing immersion brewing methods. Reason being that their extraction times are so low that is usually not practical to press a fine grind coffee. Though this isn't a direct answer to your question, I'd recommend grinding your coffee directly before brewing. This is best practice, and it means you can grind your coffee to whichever coarseness that you need.

If you want to french press this coffee I think it would be best to adjust your extraction time. If you're using an espresso grind I'd do a short bloom, then extract for 45seconds.

To eliminate fine grit, wrap a paper coffee filter over the strainer, and press immediately to achieve 45second extraction, as there will be more resistance with the added filter. If the coffee is sour or bland increase extraction time. If the coffee tastes too bitter, then try decreasing the extraction time. Bloom for maybe 8 seconds. It's hard to tell, most people press coffee because they like pressed coffee, and they'll usually use a coarse grind for this. Using a fine grind will likely negate the benefits of using a press pot, and could very well be impossible/very difficult to consistently get a good cup.


Coffee does not include any form of cholesterol, as it is produced in the liver of animals.

However, some alcohols in coffee affect how cholesterol metabolizes in human body. Thus, indirectly affects cholesterol levels.

Extraction of these alcohols are mostly related with grounds contact period with water. So, we can say you should take care about the brewing method.

For example, cold-brew increases the cholesterol levels the most. Drip-brew and instant coffee the least. Turkish coffee increases a lot. French-press increases quite much. Espresso is somewhere in the middle. Pour-over filters are increasing just a little.

More information


Is it possible to get hot chocolate using an espresso machine?

The steam wand will do a terrific job of mixing, heating, and fluffing (what's the technical term?) milk + cocoa powder into killer hot chocolate.

Personally I recommend unsweetened cocoa powder, but most people probably want a sugary drink.

But I don't think you'll want to use the main espresso part of the machine.


There was an episode of myth busters they were testing is it better to stay wired or tired and the outcome was you cognitive skills improve when you are wired on caffeine.

Now I don’t know about memory but I am sure all the answers you are going to receive will be highly subjective...but the above mentioned episode is the closest thing to a scientific answer we will ever get IMO.


How long can I keep my carafe on the warmer?

It would depend on a number or factors including temperature of the warmer and humidity in the room.  However, personally, I can begin to taste a difference after as little as 45 minutes on the warmer.  I tend to drink two cups of coffee pretty quickly to avoid this.

Coffee is a product always best fresh, but how long before your palate can detect that it isn't fresh any longer is a matter that varies by individual.  My wife will drink coffee from a pot that has been sitting for four hours plus; after about an hour and a half I'll throw the pot away and make another.  Your own mileage may vary.


I like a really mild tasting coffee, not to bitter, a little bit sweet but not overly sweet, what beans have this kind of flavour

I think your question may need a bit of disentangling, however I will try and deal with your main points. First there are several factors that influence coffee bitterness, and origin, albeit important is not the most influential factor. More on that later. Secondly it is not clear what you mean with "mild" coffee. Do you just mean "not bitter"? Because non bitter coffee is by no means necessarily mild. It can even be more flavorful with very fruity flavors and a lot of acidity, while bitterness may cover up a lot of these flavors.
Regardless of that I will now write some points about how to reduce bitterness.

Arabica tends to be lower in bitterness and astringency than Robusta, because Robusta contains more caffeine and chlorogenic acids. So take care you buy 100% Arabica.
The roasting is a very important factor. Dark roasts are much more bitter than light roasts, while lighter roasts emphasize floral, fruity flavors and acidity. In my opinion most people who complain about bitterness in coffee could fix that by drinking lighter roasts. Unfortunately for most people roasted coffee has to look dark brown to almost black with a glossy surface. In most cases beans like that are over roasted. So  you may want to try your dads beans with a different roast profile.
How do you prepare your coffee? Bitterness is often a result of over extraction. Make sure you extract your coffee properly so you get a flavorful, but delicate and pleasant taste. You will find instructions for your preferred preparation method here on the stack exchange, on many websites of specialty coffee shops or you could ask in your favorite specialty coffee shop.
Last but not least, origin can play a role in bitterness. Overall you could probably say (all else equal) that many african coffees are lower in bitterness and higher in acidity. You could try Ethiopian and Kenyan coffees. Ethiopian coffees tend do be very delicate, floral with nice acidity while Kenyan coffees are higher in acidity and fruitiness. Central or South American coffees are probably (all else equal) slightly more bitter, but if the roast and extraction is right, bitterness also shouldn't be an issue. They would have more nutty, chocolaty flavors. Of course there's exceptions. Panama Geishas would be relatively high in acidity compared to other Central American coffees (also much more expensive and the bean is originally an Ethiopian heirloom variety).

To sum it up though I would recommend you first focus on point one to three. In my opinion they are more influential here. I'm assuming that you are already using Arabica, but I suggest to try different roast profiles and recipes. If you already did that I would recommend you to buy some washed Ethiopian beans as they produce delicate (you could maybe call them "mild" although I don't think it's the appropriate term) cups.


It may completely be abuse of the machine, but I saw someone clean stainless steel jewelry once in an ECM machine. They put the jewelry in a sealed portafilter basket and backflushed the machine with cleaning detergent.

It seemed to clean the jewelry pretty well, but I can't say if it would be very different from putting it in the dishwasher.

At the very least, it seems to be a way to kill two birds with one stone when backflushing your machine.


What is this white spots inside my Bialetti Moka?

I believe that is corrosion of the metal depending on what is put in that container and the chemical properties of that substance can lead to wear and tear on the metal. Test this out to see if this works mix a baking soda solution and let it soak in the pot for 30 min to an hour. Then wash the pot that should remove it.


Is leaving coffee bins open in the store normal?

No, it is not.

As you may see in many other answers in this SE, Coffee SE site's answers will lead you that coffee is best stored when it's distant from air,  odor and light.

Closed, vacuumed storage is the regular way and coffee stores are no exception. On the other hand, one may expect that a store should grind coffee when it needs it. So, it won't go stale unnecessarily.


How instant coffee is prepared in the factory:

Coffee beans are roasted
They are ground very finely (0.5 mm - 1.1 mm in diameter)
The ground coffee is mixed with water in percolation columns which reaches 155 - 180 degrees Celsius.  This is the extraction process.
This mixture is then concentrated and/or dried using vacuum evaporation, freeze drying, or spray drying methods.

The result from this is what you get in the store.


Which ginseng caffee should I order to get the experience of "Caffe al Ginseng" in Milano?

According to Italian wikipedia, the first ginseng coffee popularized in Italy was an instant packet drink also sold in Asia. https://it.wikipedia.org/wiki/Caffè_al_ginseng
If you're willing to go instant, you can try this: http://www.veryasia.com/ginseng-coffee/ (also available on Amazon)

The wiki entry suggests what you drank was probably espresso with dry ground ginseng. So if you don't want instant, you could get some espresso and add dry ground ginseng to the grounds. You can get ground ginseng at any Chinese herbal store. One writer, Peter Lim says a capsule (like the gelatine type you would swallow) is the right amount for a serving of coffee.

Good luck.


Are there places in Belgium or netherlands where you can buy coffee green beans for agricultural reasons?

For other people from Belgium or the netherlands who were searching for green coffee beans to farm. I found a website where you can buy them.

https://www.onszaden.nl/zoeken?s=koffie


Is there a difference between a manual and an automatic grinder?

The most important differences I think, are time and temperature.

I really don't know much technical details about grinders, but as @luser-droog said, friction will create heat and it will affect the coffee (so, motor grinders can be affected by this if doesn't manage heat dissipation well)

And of course, in all cases, time matters; so, time might be a crucial factor for someone.


The only disadvantage that I see from drinking coffee is that you don't have the time to drink tea!

At the age if 68, I average 6-8 cups of coffee daily,  and have done so for the past 50 years or so. My current job,  I got bored  with retirement,  now averages 35 - 40 hours per week involving continuously standing,  bending,  stretching,  and walking an average of 10 miles a day pushing loads up to 300lbs at a time.

Oh,  the last cup if coffee is right before bed.

If your family keeps nagging you,  take away their soft drinks and cigarettes,  then let them REALLY complain.


Options for measuring TDS - Suggested refractometers

You're on the right track with using a refractometer to measure coffee, but most people don't need a unit that expensive. There are more affordable refractometers if you don't need the VST CoffeeTools software.

One example is the Atago PAL-1, which costs around $300. This is a digital refractometer. If you want something more affordable, you can get a manual brix refractometer which will start around $20.

There are many brands of digital refractometers other than Atago, a quick Google search came up with some around $100-200, so there should be something in your price range and quality that will work for you. Good luck!


Do you re-heat the kettle between pours?

Short answer: No
By reheating your kettle between pours you introduce another variable which can mess with the consistency of your brew. The reason we measure everything when brewing coffee is to be able to isolate a single variable, adjust it, and determine its impact on the taste of the brew. Consistency is the most important thing here.
Losing one or two degrees in your kettle while brewing shouldn't have much of an impact on the taste of your brew if it happens consistently. Also, the water drops in temperature significantly when it reaches the grounds, as explained in James's video you probably meant.
Both James Hoffmann and Matt Perger recommend using boiling water for brewing because seeing water bubble (and therefore knowing it's exactly 100°C) is more reliable than having a thermometer telling you the temperature. "25 degree water looks exactly the same as 85 degree water".
My recommendation is to let the water come to a boil and as soon as it starts boiling, start your brew and don't reheat it between pours. Even though the water might cool down a little, it will do so similarly from brew to brew. If you reheat your kettle between pours, you'll have to put in on the stove the exact same way each time, which is difficult (maybe not difficult but surely finicky) to achieve, especially if you have a pour-over to worry about.
Now, before anyone comments with "100°C is too hot, you'll burn the coffee":
Coffee is roasted at temperatures around and above 200°C, you're not burning anything.
"It will taste burnt and bitter because the bitter compounds will be extracted more easily."
In that case, over-extraction is your problem which can easily be solved by adjusting your grind size.


Just think that your drink, coffee, is around 97-98% water so you need quality water to make a quality cup of coffee due the following:

Tap water, beside the calcium, will have additional components and too much calcium will give a taste of acidity to the coffee, calcium makes the water harder.
In order to get a fruity taste from your cup of coffee you need to focus on the balance between magnesium and calcium, magnesium will extract flavor from the beans ... now you know why all the coffee shop coffee taste close to each others and is due the source of water is used( all use tap water) makes them high acidity and requires sugar+cream in order to enjoy that cup :(
Sodium does make the coffee taste acidic like the calcium does so you need balanced or spring water to see difference or even distilled water but the coffee will loose drastically from the flavor ... unbalanced.

At least the bottled water you know has added magnesium for taste and is in a balance with other minerals including calcium(not looking does stay in plastic bottles ... that is a different story and think tap water pipes and source of water/process used to make “safe” for drinking)

  Note: I roast the batches of coffee home and in order to feel the
  right flavor tried distilled water, tap water and spring water;
  Currently I use only spring water fresh from the ground and filtered
  so coffee or tea doesn’t require butter, creamer or any other flavors
  added in order to feel the real taste. Same does come to sodium.Even tea does follow same path
  when does come to the water .

One more thing, boil the water and check the sediment left to compare the “tap vs bottled”, “tap vs spring”, “spring vs purified/bottled”.


This question is actually answered on the website of the coffee producer.

To summarize, the roasting process of coffee produces carbon dioxide inside the beans, which takes a while to find its way out. Sealing the coffee in tight containers would be problematic, as the carbon dioxide would stay in the beans in this way (making the coffee sour) or may let the bag burst over time.

However, not sealing coffee bags is not a solution either, as exposure to air lets the coffee get stale after a while. As supermarket coffee is unfortunately often stored for long period of time before sold, this would be problematic.

So the solution is to either (1) use a one-way valve that allows the carbon dioxide to escape from the bag without the air coming into the bag, or (2) to let the beans degas before sealing them airtight in bags. Solution (1) is probably best for fresh coffee, so it is used here. I don't know what problem is solved with such valves in pet food containers.


Do you need to use ice water in a Bruer slow drip coffee maker?

I have no specific experience with this cold brew device but a general understanding of how extraction works and experience with other devices. In short, you can definitely use water at room temperature to make cold brew (I think it is better), but there seem to be some specific issues with this cold brew maker.

In general the colder the water, the slower it will extract the solid compounds from the coffee. This is the main thing you have to keep in mind, because you will have to adjust some other variables in order to reach the right extraction. In their instructions they suggest you use a medium grind level. This is one variable you could change. Instead of a medium grind level I would use a medium to coarse grind. Another variable that you could change is the brew time. They set the device to 1 drop per second but you could increase that a little to speed up the brewing process, resulting in less extraction.

Specifically with this device there seems to be the problem, that air bubbles block the valve (see the FAQ on the website). They argue that the changing water temperature is responsible for the bubbles to appear. However if you brew at room temperature the water temperature should be much more consistent than with ice water which will obviously melt eventually and then the water will warm up. So I'm not quite sure about their logic (unless you are supposed to add ice until the brewing is over).

I suggest you go ahead and try it at room temperature, adjusting the other variables. Make sure you pre infuse properly so the grounds degas as much as possible, that should prevent too much gas blocking the valve. Alternatively you could use refrigerated water and brew it in the fridge.
Hope this helps, in the end it's a lot of trial and error anyways. Have fun brewing.


"Speed Roasting" from Coffee Tonya: Is it just as good?

Roast times can significantly affect coffee flavors, and a 2 minute roast profile is concerning.  While I cannot say I am familiar with the process they are using, I do know a decent amount about the chemistry involved when you are roasting a coffee bean.  My biggest concern would be internal development of the coffee bean.

To give you a brief run-down of roasting, without spending hours on this post..

You typically have two types of heat in roasting, conductive and convective.  There are disagreements on how best to apply heat to a coffee bean, but the traditional understanding is you apply conductive heat early in the roast and convective at the end.  The reason is because if you do not dehydrate the internal bean, you will get an insulating barrier of zero moisture encapsulating the moist interior of the bean that will result in underdeveloped flavors (sour, acidic)

If you apply too much convective heat early on, then this will typically happen.  If you apply too much conductive heat, you usually get what is called tipping which can be seen on the ends of beans as a small black spot where the plant would actually sprout had the bean been planted (this is a natural weak spot in the cellular structure that allows the plant to sprout).

To roast a coffee bean from room temp to ~400F give or take 25 degrees in 2 minutes would require an average rate of rise (RoR) of 115 degree / minute.  To give you an idea of the difference, The highest RoR I typically roast at is about 36 RoR and maybe an average RoR of 15 or 20.

My initial reaction to application of heat so quickly to a coffee bean would be that you would get over-roasted on the outside with possible tipping, and an under roasted interior resulting in sourness.

I know that timing on airbed roasters is different from traditional drum roasters, but I've never heard of them doing 2 minute roasts either so I am guessing this is a proprietary roasting system of some sort.  That being said, if you want a pretty in depth discussion on how roast times affect flavor you can check out Modulating the Flavor Profile of Coffee by Rob Hoos.  He gives a very thorough break down of what happens when you trim as little as 20 seconds off a given segment of a roast profile and how that affects the flavors in coffee.

(btw, if I deviate from my desired roast level by more than 45 seconds, the beans usually end up in the trash can because I refuse to sell them)


Spots on Moka Pot, I suspect they are mold

After the first instance of boiling the water in the bottom part, any mold will be dead. Using a soft brush will easily remove it. So this looks like oxidation damage.

As for the smell, the filter basket has a layer with holes in it, the underside of which is very hard to clean as you have to get to through the funnel.

However, I suspect the top part. There is a filter and a rubber seal. Remove the seal and clean the "hidden" part of the top filter as well as the the area all the way up. The rubber seal is very likely to have picked up a bad odour. This happens quite often when the moka pot  was too hot and burned the seal, making subsequent cups taste (and smell) like burnt rubber. These rubber seals are cheaply available as a replacement part.


I think you are on the right track with your idea. To understand what's happening you need to understand how the moka pot works and how to correctly use it. I'll explain it here quickly but there are some nice illustrations on how it works on the Wikipedia entry for it.

First, the heat should be cut off once you hear the first hissing sound. That is when all the water has been pushed through the ground coffee and the brew is ready. By construction there remains a little bit of water in the bottom chamber. That is because the spout of the filter basket doesn't go all the way to the bottom of the chamber.

When the water starts boiling, the steam of the evaporated water pressurizes the chamber between 1,5 and max. 3 bar (that is the pressure the safety valve sustains without opening) depending on the grind size of your coffee, the amount of coffee and if you tamp it (which you should not). The gas pressurizes the area above the water, which pushes the water through the spout, through the ground coffee and into the top part until the water level is so low that the steam exits through the spout. That's the hissing sound. So one of two things could be happening here:

There might still be a lot of water in the "brewing chamber", where the ground coffee is, when you cut off the heat. Then the pressure in the bottom chamber will fall and the coffee in the middle gets sucked down into the water chamber.
Pretty similar but instead of the ready brewed coffee it is some of the grounds that get sucked into the water chamber and keep brewing there in the rest of the water. It may be that it is ground too finely.

Both of these things are not a problem though, just flush everything with warm water and that's it (no detergent if it's an aluminium pot or you risk oxidation).  It only affects the coffee if you cut the heat way too early or too late.


Attempt 1

For the first attempt, I brewed it exactly like I brew my normal (water-based) coffee. I used a French Press with a light/medium roast, heating the milk in Pyrex in a microwave. The milk heated unevenly, curdling in places. Luckily, the curdled bits stuck to the Pyrex and I was able to make a passable cup. The thickness of the milk meant that it didn't want to pass through the mesh when pouring.

The predominant flavor was that of the milk. I could barely tell it was coffee, though it definitely absorbed some flavor. The texture was about what you'd expect--very smooth and rich. It was the kind of drink that makes you feel all warm and fuzzy inside.

Attempt 2

From my first attempt, I learned that milk is able to absorb and mask coffee's flavor incredibly well (after all, it's what people use to tone down overly strong coffee). This time, I heated the milk in a saucepan over low heat, stirring frequently (a rather long and annoying process for a single cup of coffee). I probably could have gotten it a bit hotter, but it worked well enough. I nearly doubled the amount of grounds and brew time.

This time, it came out with a distinct coffee smell, and about the same texture. Again, the initial flavor was that of the milk, but it had a smooth, subtle, and quite pleasant coffee aftertaste. I never got that bad taste you sometimes get a while after a normal cup of coffee--instead, the residual flavor was like you had just taken a sip.

Conclusions

I wouldn't want milk-brewed coffee for my morning cup. It feels more like a drinkable dessert.

If anyone else wants to try this, I recommend using some stronger/darker coffee. I didn't have any dark roast on hand, or I would have tried it. Give it time to brew--more than you would with water. Be patient when heating the milk, or you'll end up curdling it and ruining the whole thing.

This could probably work as a dessert drink if brewed with some spices in addition to the coffee. If nothing else, I'd say it looks pretty cool as you can see in the attached image.

UPDATE

I tried this again today with espresso coffee (Cafe Bustelo), and it turned out great. The end result was like a latte but more... dull, or smooth. I don't know how exactly to compare it. Espresso grind is definitely the right choice when brewing with milk--it's the only thing strong enough and with the right flavor profile to stand out in the milk and complement the milk's flavor.

Be warned, though, that the fine grind of espresso coffee means you will need to use a paper filter at some point along the way. Sticking a paper filter in a French Press doesn't work because of how resistant the milk is to going through the filter. It seems to jet around the sides, allowing the espresso to slip through.


The graph shown is a spider-web graph that is similar to a line graph but in a shape of a spider web. In this case, the scale (middle line, goes from bottom to top) shows the score each section can get. A blue line (or any color) is drawn according to the scale. A score closer to six will have its vertex nearer to the center of the web and a score nearer to 10 will be nearer to the outside. This graph seems to be scoring the different qualities of the coffee.

A Cupper's Correction is used when the grapher thinks that the total score (add all the smaller ones) should be higher or lower. In this case, it's two so the original total score has two bonus points.

Source for Cupper's Correction: http://legacy.sweetmarias.com/library/content/cuppers-correction

Quote:

  The cupper's correction is a term we use to measure the intangible qualities of a cup: if, for instance, a coffee totals 88 points, but it is high quality enough that we feel it should< be a 90, we add in a +2 cupper's correction.

I think the "<" in the quote is a typo.


Where to buy small batches of unroasted beans

There are several websites that sell unroasted or green beans in a range of quantities and will ship.  I have heard that Costco or maybe it was Sam's Club were selling them as well (albeit in larger quantities).  Keep in mind that shipping can be prohibitively expensive for small quantities.  I order 12 pounds at a time from Sweet Marias and they ship in a flat rate USPS box; so shipping is very reasonable and only adds roughly a dollar per pound (for a twelve pound order).

I know are other good websites out there, but Sweet Marias has provided me with excellent customer service when I've had order issues (burst bags in shipping) and their website is very thorough, including forums, education and product reviews/recommendations.


Is there a way to drip-brew coffee with lower acidity?

There are at least three ways to reduce acidity.

One way is to roast the beans more, to a dark level. I think that is the main way if you want to stick with your beans. This is inline with MT San's comment and related answer.

A second way is to play with the speed of dripping. The idea is to find a speed of water flowing through the coffee ground that gives better results (depending on your goal---here lower acidity). A slower water flow will keep the ground longer, so extract or destruct more compounds---thus a different flavour. In my limited experiments here, faster flow brings more acidity. But I am not confident on the generality of this result.

An alternative, when you are fine with changing beans, is to get a variety or a blend that results in lower acidity. This is not as efficient as a dark roast, but you can get more flavours and variations. Roasting artisans should be able to offer good candidates.

There may be other ways, but I have no other experience.

Later...

Thanks to @Chris_in_AK, I have recalled another alternative: Cold-brew. The question refers to "drip-brew", so cold-brew is border-line, but it is technically a drip, with cold water, so here it is.

Cold brew allows to extract very different flavour profiles. The slow, soft process takes ages (8 to 12 hours), for often surprising results. And warming up the result leads to yet again different flavours.

In my experience, drinks are less acid with coffee brew. I do not use a wide range of beans, so please keep in mind that this claim may depend on the species. Also, the roast level leads to different results---exactly as a hot-water drip does.

Cold brew emphasizes "green" or "herbal" notes, though. It is, I believe, worth a try as acidity is different, but it is yet different from "usual coffee drinks". Well, production is hard too.


What are alternatives uses for an espresso machine?

Sterilizing smaller items (pacifiers, bottle nipples, toothbrush
heads, etc.)
Loosening threaded bottle and jar lids for honey and other sticky substances
Cleaning small items (watchbands, rings, bits of grunge around the pads for your eyeglasses)
Toothpaste cap cleaning Quickly heating water for tea/chai
Quickly heating water for shaving bowl
Melting butter Blocking hats


Are there any Alternatives to using a Refractometer to determine extraction

I guess measure density just like you would in a college-lab? Just use a graduated cylinder.

Extraction is mostly about how efficiently you can extract coffee solubles with an amount of liquid. Since refractometers are pricy, you can use a 0.1g scale and a graduated cylinder, to measure how heavy your shots are. The denser the better, however you also have to be practical with how long your shots take to be pulled.


What influence do the dry residuals of previous coffee in the cup have on the drinking experience?

You're actually asking two different questions.

The minute amount of coffee left to evaporate in the bottom of a cup will have completely oxidized and lost virtually all of its volatile compounds (i.e. It probably wouldn't taste very good if you reconstituted it on its own). So when you add more fresh coffee to that cup, yes, you are essentially adding a minute amount of an external (and somewhat off) flavor component to your brew.

Now whether that flavor component contributes to any any perceptible change in flavor is highly debatable. Line up 100 coffee drinkers in a blind tasting, and I suspect there would be no statistically significant detection between "100% fresh" and "Christian's 0.083% dust-like coffee residuals."

Your analogy to washing tea cans in a dishwasher is a bit off. Washing containers in a dishwasher is generally known to leave a perceptible taste of soap on the container. Soap is completely foreign to the coffee-tasking experience so it is easily tasted if it is present. But the residuals you are leaving behind in your unwashed-coffee-cup study are still essentially coffee (somewhat off coffee, but coffee nonetheless). So mixing the equivalent of "a few drops" of off coffee in a hot cup of fresh I suspect will have no perceptible effect on taste.

I also suspect that your coffee cup experiment is not evolving over the years. The metallic cup is likely stainless steel or perhaps aluminum (and most coffee cups are made of ceramic). In either case, the cup is largely stainless, so you are not likely building up any patina… so you are essentially "washing away" the previous day's experiment each time you add a fresh cup of hot coffee. There should be no substantial, cumulative effect.


What roast level is recommended for cold brew?

I'm going to answer this in terms of flavor, and then acid.

Generally, people choose more lightly roasted coffee to preserve the terrior flavors of the bean. These flavors usually come from unstable molecules that deteriorate quickly after the coffee is brewed. When coffee is brewed and consumed relatively quickly, the drinker can enjoy those flavors. Cold brew produces a more muddled mixture of flavors and relies more on mouthfeel and big flavors like sweetness, savory, earth, chocolate, etc. More delicate precise flavors are lost. It is also important to note that some fruit, vegetal, and herbal flavors are enhanced by the presence of acid, like adding lemon juice and tarragon to a fish filet.

So, it you are trying to avoid acid but you love the fruitiness of say, a medium roasted Kenyan single origin, you could cold brew it and see if you still get the flavors you want. If you hear about another light roasted coffee that has strong sweetness but is more acidic than you usually like, try it as a cold brew.

I.e. if acid is what is holding you back with specific coffees you want to try, try them as a cold brew. Just know that the lack of acid in the cold brew may make it a little lack-luster compared to a traditional cup, especially since tasting notes are made when evaluating hot brewed cup.

Darker roasted coffee as already lost more of the bean flavors and gained more roast flavors. If anything, I would say that a darker roast is going to have a more consistent flavor between hot and cold brewing simply because more of the delicate flavors have already been burned away. I would bet that Kicking Horse and Blue Bottle suggest a medium roast for cold brew because a medium roast preserves the beans own characteristics while introducing the roast flavors. This is why single origins are usually roasted to full city or less.

In summary, I would suggest that you find a coffee you like already as a french press or pour over and cold brew that regardless of roast. Lighter roasts may lose some of their complexity in a cold brew, darker roasts will mellow even more in a cold brew. As backwards as it is, I hope this helps!


Does aeropress coffee change flavour after several hours?

All coffee changes taste over time - it is full of relatively fragile organic compounds that will change over time.

Even in a vacuum flask (without exposure to light), the coffee will keep chemically reacting with itself. There is also oxygen in the bottle which will aid the breakdown of various of the compounds.

There really is no way to perfectly preserve the taste of fresh coffee unfortunately!


I only know of two connections between coffee and nausea. The first is caffein withdrawal, which in your case obviously doesn't apply. Secondly there is some evidence, although it far from being clear, that coffee might be bad for people suffering from reflux disease. See for example here.

According to that source, gastroesophageal reflux might be triggered by coffee (among others). However it is far from clear, that it really does with studies showing that dropping coffee consumption doesn't significantly change the symptoms to the better.

I suggest you talk about this with a doctor or dietary specialist. This is pure speculation, but maybe you are allergic/intolerant to one of the compounds found in coffee or it is some kind of psychosomatic response. The expectation of becoming nauseous after drinking coffee that leads to actual nausea. Maybe there was some unrelated nausea that you connected to your coffee consumption. Or maybe your nausea is entirely unrelated to the coffee and just happens to coincide with it.

If the problem persists and a doctor couldn't help you, maybe try green/black tea. They contain caffein and can have a similar, somewhat more mellow but also more persistent energizing effect.


I think it is generally regarded that beans are still 'fresh' within one month of roasting where the flavour profile of the bean will change over that one month. Dissecting it further, people tend to agree that beans should be at their peak within 2 weeks of roasting. Past a month the bean should show noticeable signs of decline in the flavour profile, losing most of the brighter notes and acidity and providing a much flatter flavour profile as most complex compounds in the coffee would have disintegrated.

You mention that your friend has had those beans for over 4 months, even if measured since the roast date, you can safely say that those beans are stale. At this point there's really no difference between getting rid of them now or later as they should not degrade much further if at all.


How can I identify whether coffee is expired or not?

Roasted coffee beans behave differently during storage than raw ones. Heat treatment not only changes the color, smell, taste and even the size of the coffee beans, but also reveals the coffee – a bouquet of aromatic oils that evaporate very quickly. The shelf life of roasted coffee varies greatly depending on the storage conditions.

Processed grains, which are stored in a conventional, leaky container-jar or box – have a shelf life of 10-14 days.
Packaging in household conditions using foil will extend the shelf life up to 3-4 weeks.
Fried grains Packed in sealed four-layer paper bags can be stored for up to 6 months. If the packages have an additional polymer coating inside, the period increases to 9 months.
Roasted coffee beans can be stored for up to 12 months in heat-sealable film or foil-based packages. Such packages have a special gas discharge valve. It is required for freshly roasted coffee beans, after roasting, they continue to release carbon dioxide, thanks to the discovery of the smallest internal capsules. If you let the beans completely exhale, then they will be subjected to strong oxidation.Fried grains in opaque jars with hermetically lapped lids, Packed in a factory way, also have a long shelf life-up to 18 months.


What is the coffee & water ratio when cold brewing?

It depends where you look. When you create the concentrate some people say 1:2, coffee and water, some say 1:1. It really depends on how you like it.


Your recommendation and advice for Turkish coffee blends

I still think this is very subjective. Still, some facts may help.

Brazilian Santos is the most commonly used beans in Turkey for Turkish coffee. However, it is not my favorite. Other people may like it a lot. Santos is something like a mixture of many varieties, though its taste may fluctuate a lot with respect to your sources. The main reason that it is used in Turkey is the fact that it is cheap.

Ethiopian Harrar, on the other hand, is one of my favorites. I don't have any concrete proofs but I believe that it was historically one of the beans used for Turkish coffee during Ottoman times, together with Yemen Typica.


Should I flush the Nuova Simonelli Oscar II before pulling a shot?

Flushing helps clear any residue that might be left inside the machine or grinds stuck to the group screen before pulling your next shot. It also helps bring the group head up to temp before you lock the portafilter, so your first bit of hot water doesn't get cold as soon as it hits your puck.


I think you're talking about coffee bean chaff, it's pictured after roasting in this blog. These are blonde flakes the come off the beans during the roasting process. In most commercially sold coffee I've seen, the chaff has been removed. When I roasted my own coffee I didn't bother because it's not so easy to separate them from the beans and they are harmless (at least for brewing).
In your case, it seems some of the chaff was still stuck on the beans after roasting, but it came off when grinding the beans. I wouldn't worry about it too much for brewing coffee, but if you want to use the ground beans in another dish, it might be better to use a sieve to strain the chaff.


Cafe Mai vietnamese coffee - what is the US equivalent?

I would say that the easiest way to get authentic vietnamese coffee in Washington DC would be to go to an asian supermarket and buy a pack of vietnamese coffee. I've never been to DC, but I just googled "Asian supermarket in Washington DC" and also "Vietnamese supermarket in Washington DC" and plenty of option show up. So it should be easy to pick one that's close to you.

Other than that vietnamese coffee is of the Robusta species and the roast profile is quite dark. So you can also just go to a well sorted supermarket and buy a pack of Robusta dark roast beans/grounds, preferably of vietnamese origin. It will be more or less the same as the coffee roasted by vietnamese roasters.


What does wetting the coffee for 30 seconds do?

Making coffee is all about extraction. The compounds you find in coffee beans that add flavor dissolve at different moments of the process. Some dissolve almost instantly when the coffee grounds come in contact with water. Like for example caffein and the more acidic compounds. Others take a while before the water dissolves them, like bitter compounds and sugars. The goal is to have an even extraction. To get the best possible flavor out of the coffee. You want some sugars in there to give it sweetness, but you don't want too much bitterness. You want fruitiness and acidity, but you don't want it as sour as lemon juice. So you need to balance the extraction.

There are different variables influencing this process, but they all come down to how fast and much extraction is happening. The grind size, the water temperature (and mineral content) and the brewing time just to name the most important ones.

Wetting the grounds, or blooming, is preparing them for the extraction. When coffee is roasted CO2 gas is trapped inside the beans. Wetting the grounds, without water passing through the filter (for drip coffee where blooming is most important, certainly more than for full immersion techniques like French press) has the effect of the CO2 being released to ensure an even extraction when you are brewing. There are several straight forward reasons for that and some more technical ones.

Blooming prevents channeling of the water (the phenomena that all the water will flow through small holes of grounds instead of saturating all of them)
If you don't bloom the gas in the beans will bubble upwards pushing the water away from the grounds which results in channeling and uneven extraction of the particles that are trapped inside the gas bubbles.
Imagine your grind, it's made up of particles of different sizes with most of them somewhere hovering around the size you actually wanted. So when you start pouring water without blooming the small particles will soak up the water faster than the bigger ones and will obviously start extracting earlier. In the end that will result in over extracted small particles and very under extracted bigger particles. By pre infusing the grounds you even that out a little bit. By adding just enough water to infuse all of the grounds without already extracting, you start from a more even level. The smaller particles will still extract more than the bigger ones, but the extraction levels are evened out, because the starting point is more leveled and extraction begins at the same moment for all grounds.

"Why should I pour remaining water in batches anyway?"

This is more a matter of style. Some Baristi prefer it that way and others pour continuously. More important is that you don't brew excessively long or short. Between 2,5 min. and 3 min. is a good time (for Hario V60, different for other pour over methods). Some say that pouring in batches helps being consistent, but it's not something that's necessary. I brew very consistent (measurably with a refractometer that measures total dissolved solids or TDS) and I pour continuously.


Is diluting filter concentrate after the brew the same as brewing with the additional water?

No it is not the same. The brew ratio is important to extract the right amount of solubles from the coffee, ideally all the pleasant ones and only few of the unpleasant ones.
If you brew with less water, you'll dissolve less of the coffee's goodness, and diluting that will lead to a thin coffee compared to a correctly brewed one.
Conversely, if you brew with too much water, you'll extract bitter substances you won't like, so if you like a thinner coffe (like an americano) it's best to brew normally and then dilute.
Unfortunately, the Aeropress is not really suitable to serve multiple guests.


Is this kettle (Moka pot) intended for re-brewing coffee?

The photo you have posted is a standard moka pot (See Wikipedia entry here) by a well-known brand, actually the inventor of the moka pot.

You should fill it up to the safety line. You should see it when you fill it. That line is generally curved inside. Filling it more than this line may cause high pressure due to evaporation of water and it may cause harm.

This equipment is not intended to re-brew coffee, but to brew coffee that tastes similar to espresso on the stove. (8 grams of coffee per 30 ml of water is the common accepted ratio.)

If you are interested in re-brewing used coffee grounds, you may also check this related question: Brewing with the coffee grounds twice?


What’s the best all purpose zero retention grinder for single dosing?

I have a Baratza Sette 270 along with the S2 Cone Burr which is better suited for courser grinds and have been very happy with the result.

I like it for its vertical drop of the beans straight through the blades into the cup, rather than having to be shunted to a chute off the side.

While I find I still have to use the Ross Droplet Technique and give a few slaps on the lid during the last couple of seconds while it is grinding, when I do that, weighing the coffee before and after shows little or no difference before and after. (Can't say the same for my previous grinders that I had to thump hard to get all the grinds out.)

I use it happily for aeropress, moka pot and siphons. The reviews mention there's an upper limit of the coarseness the Sette's can produce, but it has been fine for me so far.

There's also the 30 and the 270Wi models in the Sette range depending on the features you want and your budget.


Does the coarseness of the ground coffee affect taste

Required reading for any aspiring home barista: https://www.home-barista.com/tips/espresso-101-how-to-adjust-dose-and-grind-setting-by-taste-t16968.html

Basically, coarseness of the grind influences the balance of bright and bitter flavors: coarser reduces bitter flavours, finer reduces acidic flavours. But it all interacts with the flow rate; see the diagrams in the linked article.

Tamping pressure itself is not really a factor, you should keep this constant and only modify grind and dose.


What is Navy coffee?

No one really knows for sure. Some naval vessels used to put salt in the coffee either to kill the bitterness (or to help stay hydrated), but it was neither a universal or permanent practice.

William Ewing, QM1(SW) USN (ret), Quartermaster E-6 has this to about the subject:

  When navy coffee was 50% chicory, 50% cheap coffee (most of my career), it was a dying practice, based on previous coffee that was very bitter. Nowadays, the 50% chicory formula is not bitter enough to require that, and many ships get Starbucks, which they then mix with the chicory coffee to smooth the taste even more.

  Now, for a while, Denny's had some bad coffee, and for over a year, my friends and I added salt to kill the bitterness and extra sugar to overpower the salt. Then Denny's switched blends to one not as awful, so we could drink it without salt. - Do Navy people put salt into their coffee?

Other sources say the complete opposite:

  I had to make many, many pots of coffee as a mess crank (one who spends their first 90 days or so working on the mess decks. Think of it as KP for 90 days straight).

  We used a large commercial drip coffeepot and coffee, period. No salt was added, at least I never added any. That it is strong comes from the fact that the Navy has no contracts with suppliers that have decent coffee.

  It is possible that the salty taste does come from the fact that shipboard water is naturally salty. When a ship is in port, she's hooked up to local water. IIRC, ships at sea have a special desalinization process that isn't perfect, but it comes fairly close. - How the Real Men in the Navy Make Their Coffee

For a number of years, I used to put salt in the grounds to help remove the bitterness of the coffee. Please not that this was not navy coffee and I was making a 100 cups at a time. No one ever complained, but that might have been to sure dumb luck too.

The Urban Possum has this to say about Navy Coffee:

  Use an economy-brand coffee. Mother Parker's, for example, or Chase & Sanborn. If you have to talk in terms of roasts, these brands are a light to medium--perfectly acceptable to a majority of people. Their virtue is that they're cheap--hey, it's Navy coffee. We're talking government suppliers here.
  Use 2 level tablespoons for each 8-ounce cup. The standard measure for coffee is 1 level tablespoon for a 6-ounce cup. The power of Navy Coffee does not derive from the strength of the roast, but from the amount of coffee used, so as you can see, this one is stronger than most. Some old chiefs like the coffee so strong that it actually seems chewy (that comes from the tannins in the coffee and their effects on the tooth surface), but we don't need to go quite that far.
  Salt the grounds before you begin brewing. Salt, as in ordinary table salt. The measurement is a pinch, which is about 1/8th to a maximum of 1/4 teaspoon per 5 cups brewed. This is the secret to True Navy coffee: the salt will cut the initial bitterness of the coffee, but takes nothing away from the aroma. Don't worry too much about the taste, Navy coffee won't taste salty unless you use too much of it.

As a side note, the navy often employs the term a Cup of Joe to their Navy Coffee. Where this tradition first came into use is unknown but some believe it was due to the Secretary of the US Navy, Admiral Josephus “Joe” Daniels who abolished wine (or alcohol) on Navy ships in 1914.  Thus, coffee (the next best thing) was the beverage of choice for the sailors.


Choosing grind size should be considered for older coffee beans?

The reason this is suggested is because beans essentially lose flavor over time. They go stale and their oils go rancid. Grinding finer exposes more surface area of the bean to the brew and helps you eke out a bit more flavor when the bean is old and stale.

However, doing this for pour over can backfire as pour over is highly sensitive to grind. Too fine and your pour over won't drain; the filter will clog.

Try it first with your normal grind, and if that's no good, dial it one or two clicks finer. Much past that and you're in no go territory for the brew method most likely.


What is the purpose of the crimp on a moka funnel?

The crimp is there to support the reducer! The reducer slots into the funnel, and sits on the ridge. You then put coffee on top of it, allowing you to use less coffee in larger pots.


Should the filter capacity be matched to the brew amount?

I would agree with you.  With the thin flat layer of coffee the hot water is just pushing a hole right through it.  You are not getting nearly the contact time of a full size brew.

If it was conical or V shaped filter then it would better accommodate different size batches.

On that pot it does not look like you could just simply use a different filter size.


Why are lattes often served in big, wide cups?

It may be just me, but I think it has to do with aiming for a ratio of foam to liquid in each sip.

Basically a taller cylindrical cup with the same amount of foam on it would cause the first couple of sips to be mostly, if not entirely, foam. With a shorter wider cup you can have a lot of foam, but in a thinner layer, allowing for a more balanced sip and better mouth feel through the duration of the cup.


Scratches on the upper chamber of newly mochapot!

Return it. Forget about heavy metal poisoning. That's not a big concern. The bigger concern is that you'll never be able to clean inside those scratches. It'll make your brew taste terrible with time and use, and risk of disease (fungus in particular) will rise with time.


What's the recommended coffee to water ratio for cold brew?

First, make sure to study What do I need to start cold-brewing. But since concentrate is not discussed there, I don't think your question is a duplicate. Your French press concentrate could last a couple days, depending on the consumption.

Assuming you divide the volume of the French press by 5, you would need 1 part of ground coffee (the usual coarse grind you use in the press; extraction is weaker at low temperatures but the time makes up for it even with coarse grind) and 4 parts of fresh room-temperature water, which you gently mix and stir. The coffee should sit for about 12-16 hours at room temperature. Then plunge, and here is the concentrate. To dilute, use another 8 parts of cold water or milk (or better, start with 5-6 parts and taste to determine whether you want it still thinner).

Here's my favourite article that discusses dripping methods as well.


Can I brew espresso with 14g portafilter basket?

Turned out that the problem was in my grinder which failed to grind fine enough. After reading the online grinder manual (which unfortunately wasn't included with the grinder itself) I discovered the following section:

After the first few pounds of coffee, the grind produced at the lowest setting may not be fine enough for espresso. To shift the grind range finer, a small washer (included) can be installed below the cone burr.

After installing the extra washer, all my problems went away.


What variables cause the Gesha/Geisha coffee varietal to be priced so highly?

Geisha is so pricey because of a lot of marketing true. However it is extremely difficult to grow.
On a farm is Costa Rica this past June the farmer was having a difficult time with his because the root system is not as robust as other Arabicas.
Another reason for the price is that the yields per bush are lower.

Here is a good article on it: Geisha Coffee According to a 4th Generation Panama Producer


Where can I buy dried coffee cherries in the USA?

Nossa Familia Coffee, a company based out of Portland OR, sells Cascara (i.e. Dried Coffee Husks) from Guatemala.

Hope this is helpful


Is cold coffee stronger than regular coffee?

Cold brew generally has a higher concentration of caffeine due to the process of which it is made. Somewhere between 1:4 and 1:8 caffeine to water ratio. Whilst regular coffee is somewhere between 1:15 to 1:25.

If you want to dive deeper into the caffeine in cold brew, you can check out this link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5740146/


Is coffee grinder adjustability worth the higher price?

You absolutely want to be able to choose grind size - even if you have a preferred brewing method and beans, you still want to be able to make some adjustments up or down if necessary. Even more so if you are going to experiment with brewing methods, where the required grind size ranges from super fine powder (Turkish Mokka) to coarse grain (cold brew). And it is a good idea to pick a grinder that has its strength at the coarseness you need most - few will actually cover the whole range.
That said, the really important detail is how homogeneous the grind is. If you have a wide range of particle sizes, you will get over and under extracted coffee at the same time and it will be a compromise at best.
That’s why I would strongly recommend that you invest in a burr grinder, that should be the kind where you can set and adjust the grind size. As said before, read a few reviews before selecting the model that matches your needs and budget.
Blade grinders work like food processors, chopping up the beans with a rotating knife and the longer they run, the finer the grind will be - so the time you run them is sort of a grind selector. By design they produce a less homogeneous result (depending on how the blade hits the beans, some particles will be bigger, some smaller), which will sometimes work for coarse grinds, but not for fine ones. They are often cheaper, though, which is why some users pick them over burr grinders. I would not choose one if possible.
There is a reason why some pros recommend to spend equal amounts on your grinder and your espresso machine. If you are brewing with a low-budget method (e.g. pour-over by hand), the grinder will likely be the most expensive piece of equipment - and probably worth the investment.


Milk texturing issues on commercial machine!

As far as I can see you are already experienced. Still, I can give a basic recipe that may help.

You should introduce hot air of course for bubbles and also to heat the milk up.  Make circles with the wand inside the milk. Around 70 degrees Celsius is known to be good for heating milk for bubbles.
Then, you should stay on the surface. The wand should make some angle with the normal, so occasionally wand is in the thin surface of milk and air. There you can hear some hissing and whistling sound. Hearing the "paper tearing" sounds on the surface is important and told that they introduce micro bubbles.

Then, you can quickly (to not overheat) repeat these two to push the micro bubbles formed on the surface to the bottom of the jug and form new micro bubbles on the surface.

Do not forget to knock the jug to a massive wooden surface to push the liquid milk to the bottom and place the foam to the top of the jug after you finish.


Had once, made of dehidrated leaves. Lighter than green tea, it ressembles rucola (arugula, in the US).


What's the simplest/cheapest coffee maker that can make a good latte automatically?

I suggest you that do some research on superautomatic machines, there are plenty of options and we can discuss for years on which one is better (or worse).

You have to consider your budget I'll say. There are many machines, many brands, many functionalities, etc... But you'll never produce a great latte, because no machine (someone correct me please) can steam milk automatically with the consistency of a human barista. Most of automatic machines only froth the milk.

Maybe if you could present us more options or specify your constraints, we can be more useful.


What differentiates a $100 coffee machine from a $1000 coffee machine?

More expensive coffee machines typically have better "plumbing", including some and even all of the following:

2 boilers / HX to allow for frothing and brewing at the same time
Preinfusion
Copper boilers vs. cheaper aluminium versions (guarantees better temperature stability)
Larger boilers, allowing for more shots to be drawn/ milk to be frothed
Wider portafilters (which in some peoples' opinion gives better flavour)
3-way valves to allow back-built pressure to evacuate
a real steam wand, no gimmicky plastic ones that promise the world and don't deliver
the ability to be plumbed (connected to your water drain so you don't have to manually clear out the water tray.)
The option of vibration vs. rotary pumps (which are quieter, although I think they are more likely to break if there is no water)
Customisability of technical factors (pressure, temperature) which gives more control for our crazy data-obsessed coffee needs :)

Now this doesn't mean you can't get good coffee on a cheaper machine. You're just going to have to put more effort in it and get more variable results. Which is more than fair for most people.

As for the price difference, most of these features will raise the price by themselves and a lot of the more expensive machines are hand-made as well.

Last point they are also very pretty and a status symbol, not to the extent of let's say a very expensive watch but it does sort of feel that way sometimes.


How and when is flavoured coffee flavoured?

This site seems to suggest that the best time is just after the beans are roasted and still warm and "open", which makes some sense.  However, it does state that many flavorers cold flavor the beans and simply add more flavoring oils to make up for the reduced absorption.  I can't think of anyone that would flavor the beans before roasting.  Not only would the high heat of the roasting risk degrading the taste of the flavoring oils, it would also affect the roasting process and flavor the roasting equipment.

As for distribution, I believe most of the flavoring agents are fairly potent and the process is a sprinkling or pouring then mixing, and not a soaking.


The way I understand your explanation this should, in essence, make a turkish brew. In other words, it can be done, no problem.

The thing to consider would be your personal preference; not everyone likes to have their grounds swimming in their coffee, so as mentioned in the comments, pouring the insides into a drip filter might be an option to consider. If you do however decide for a turkish brew, remember to let it sit for a while so all the grounds settle at the bottom, and don't drink the last part (where the grounds will be)*.

*Or do, if you really want to. Almost no one does this as it tastes horrible, but my grandma actually used to eat the grounds at the bottom with some sugar, so I guess exceptions exist...


Could preparation method make coffee more acidic?

This is a perfect follow up to the "What coffees are the least acidic?" question!

As always, Lets answer it with some data! My company uses machine learning, data science, and sensory science to build flavor profiling and quality control tools for the craft beverage industry.

TL;DR: Yes. Preparation has a significant affect on the flavor profile of coffee - including the level of acidity.

Distribution of Acidity by Brewing Method

If I may present to you... the distribution of acidity in coffee by brewing method!
Clearly and without surprise, Espresso (coffee extracted under pressure) is the most acidic preparation method, on average. French Press (full immersion brewing) is the least acidic, and V60 (a type of pour-over) has the widest range.

But is there something else going on here?
What if there exists a conflating factor such as green processing, roast level, or growing environment? Some of these questions we're already answered in the link above, so lets focused on the remaining question - how does the origin of the coffee effect the perceived acidity of the coffee by brewing method?

Acidity by Brewing Method Controlling for Continent of Origin

So is the effect of brewing method consistent? No.
What we're seeing here is that each continent tends towards a different green processing technique, and thus a different optimal level of roast - all of which exert as much influence over the resulting level of acidity in the flavor profile of the coffee.

Please just save me from exogenous variables

Oh... you should have just said so....

This is a conditional inference tree mapping the distribution of acidity scores to a series of categorical variables.

Where:
C is Country
P is Preparation
G is Green Processing
and the bar plot shows the distribution of acidity

Country is clearly the most used variable in creating this tree, and interestingly, Green Processing is only used as a splitting rule when a country has a variety of green processing methods in common use.

Please leave a comment if you'd like me to add a variable or further analysis to this answer!


The owner's manual for your specific model should have good instructions. There are good tips and videos online for other grinders, but I don't know how well they apply to yours.
The general idea is to gently remove the hopper, bin, gasket, and similar parts, and remove whichever side(s) of the blades are designed to come out. Vacuum out the coffee dust, then use a small wire brush to loosen more coffee grounds, and vacuum again.
A thin wood kabob skewer is a good tool for cleaning the corners.
The hopper and such parts are probably washable. Do not get water on the grinder blades unless the manual says that's OK.
I have not used cleaning pellets but I'm skeptical that pushing additional stuff through will clean out the accumulated dust and oils from the path. If you do try pellets, follow them with some coffee beans as a "chaser" to minimize the pellet dust in your next batch of coffee.


Is there any process after roasting coffee?

Typically after roasting coffee there is a rest period during which you don't want to use the coffee.

Roughly 85-90% of carbon dioxide contained in a coffee bean after roasting will be released in the first 24 hours.  You CAN immediately brew coffee with fresh roasted coffee, but the flavors will not be fully developed, and you might get a metallic taste in your brewed coffee which is a side effect of the carbon dioxide.

At my shop, we allow the coffee to rest for 12 hours before grinding for the customer, and we don't cup coffees until they have rested for a minimum 12 hours.

Additionally, there are some coffees that benefit from longer rest times.  Some recommend up to 10 days rest time for espresso because you will get higher extraction yields (tds yields) after a long rest period (per Scott Rao who is an expert on the subject).  Other coffees like some Ethiopians will develop more pronounced floral / berry flavors after a slightly longer rest period of around 5 days (recommended by Joe Marocco over at Cafe Imports if I recall correctly)

Other than this rest period and grinding, there is no process that needs to be accomplished after roasting coffee.


The Short, Tall, and other sizing names are adopted by Starbucks to denote their own serving sizes. Any use in terms of coffee-serving sizes were coined initially by Starbucks which subsequently led to other coffee shops following suit as an established method.

The list of sizes are as follows:

Short 8 fl. oz. / 240mL
Tall 12 fl. oz. / 350mL
Grande (Big in Italian) 16 fl. oz. / 470mL
Venti (Twenty in Italian) 20 fl. oz. / 590mL for hot drink or 24 fl. oz. / 710mL for cold drink
Trenta (Thirty in Italian) 30 fl. oz. / 920mL

As you can see these words are fairly generic but are used in this way as size-naming convention by Starbucks.

Costa also uses a different size-naming convention based off of Italian words.


How to save over extracted coffee made using Dutch cold brew method?

Well, when you are talking about cold-brewing methods, you will always want coarse ground coffee. If you are set on using this finely ground coffee in your Dutch Coffee Brewer you will want to try a few things.

First, use much less coffee. Yes, it will still over extract over the same time period but will not be as strong. This is probably the worst option.

Second, brew faster. I know that in a Dutch Brewer this is more complicated than just letting it sit for less time. If there is a way to put more water through the grounds in less time, you will want to go with that.

Otherwise, use a different brew method for the finely ground coffee and buy new coffee for your Dutch brewer.

Hope this helps!


If I leave my brewed coffee to rest, will it lose caffeine?

Yes, but not in any significant or noticeable amounts.  Caffeine is stable in solution for quite some time.  Considering a average cup of coffee (~100mg of caffeine), you may lose a few milligrams of caffeine over an extended rest period.  Given that caffeine content varies in any given cup of coffee (many sources list variations as wide as 60mg to 200mg, or more) you are unlikely to notice any difference in the caffeine content.

What you may notice is a difference in the taste.  They are many suggestions out there on how to cold brew coffee.  It may be worth your time to research an alternate brewing method.


How much caffeine delivered by eating coffee grounds

Well, eating coffee beans provides you with much more caffeine than drinking coffee. In comparison with the 95 milligrams in 1 cup of brewed coffee, a 28-bean serving of dark chocolate-covered coffee beans contains 336 milligrams of caffeine. So if your capsules could hold one bean, lets say, that would be roughly 12 milligrams of caffeine per bean.


Calculate diluted concentration of cold-brew

The math is fairly simple. You know for how much concentrated cold brew you will be using that it is at a ratio of 1:4. Since the resulting concentration of the cold brew is constant (since it has already been brewed) we only really care about the parts of water that are in it; 4 parts.

Therefore to calculate how much water you need to add to dilute your 1:4 concentrate into a 1:15 cup, divide the amount of concentrate you are using by 4 and then multiply that by the remaining parts you wish to add, which is 15 - 4 = 11 which gives you the amount of water you need to add in whatever units you measured the amount of concentrate you started with.

Using your example numbers:

Start with 100g of cold brew concentrate at 1:4 ratio. Each part of water is therefore 100/4 = 25g. The amount of water you will need to add is therefore 11 x 25g = 275g to result in a total amount of 375g in your final cup.

Check the final answer by doing a reverse calculation. If the concentrate is 1:4 and you have 100g of it, it means you started with 25g of ground coffee. Therefore making a 1:15 ratio cup of coffee with 25g of coffee means 25g x 15 = 375g of water must be added.

The answers align.

In general:

For an amount of cold brew to be diluted, c units, which has a coffee-to-water ratio of 1:n, the amount of each part of water in the cold brew, w equals c/n. The amount of water to be added to achieve a final ratio of 1:m is therefore w x (m-n) units.

Units are any form of measure of the liquid mass being used, in g, mL or others.


Light-colored matter clinging to roasted coffee beans

What you are likely seeing is the silverskin of the coffee cherry.  Green coffee beans prior to roasting generally still have the silverskin intact/attached.  As the bean expands during roasting and the silverskin dries out, it generally comes off.  Part of the roasting process is some sort of agitation and airflow to remove this chaff.  Depending on the roast level and other mechanical factors, more or less of the silverskin may be removed.  On lighter roasted coffee with less expansion you can often see bits of silverskin along the seam on the bean.  Some processing methods prior to roasting also remove less of the silverskin, "dry processed" coffee in particular tends to be more chaffy when roasting and may require a longer time agitating or smaller roast batches to remove chaff.

Many of my lighter roasts end up with a bit more chaff than I'd like.  Like most anything involving coffee, you can find differing opinions on how much it affects taste.


Why do I feel lousy, low, out of energy after the high coffee gives?

This effect is known as caffeine withdrawal. It's normal that you may feel a bit loose of you don't have caffeine after a while. The whole set of adverse effects of caffeine withdrawal is enlisted as:

headache
fatigue
anxiety
irritability
depressed mood
difficulty concentrating

according to WebMD.


Convert Mahlkönig EK43 settings to other grinders

I had the same question as well. The Mahklonig scale is from 1 (fine) - 11 (coarse), based on some images, so you could assume that 7.3 is about a drip grind, and then adjust to taste based on results


FDA has no official guidelines on serving size, so your serving size is either determined by the product manufacturer, or whatever you want it to be. We don't know what brand french press you have but if it was Bodum for instance:

  Coffee is measured in 4 oz. cups, so our 3-cup press will brew 12 oz.; a single serving.


What is the point of having a Q&A website dedicated to coffee?

Someone is new to the world of coffee, (it is not a day to day task for them and there are hundred of ways to make coffee from all over the world) and they  have a question about coffee. They do not know anybody who is knowledgeable about the subject.
They turn to the interwebs to find information. They do  a web search but there is so much crap and misinformation to filter out that a good and correct  answer is very difficult to find, so they think Gosh why don't i put up a site were  anybody can ask a question about coffee and those in the know can post answers to those questions.
The best answers will be voted on so they rise to the top and eventually a correct answer will be chosen. Misinformation will be called out and not allowed to misguide.
In the future if somebody else may have the same question and they do an interweb search on it, one of the search hits will be the Question and Answer  site where a correct answer was given to the very question they are wanting an answer for.
Perhaps this could work for All kinds of things
Even for questions with seemingly obvious answers like "What is the point of having a Q&A website"


Is there a difference between cold brewing in the fridge vs room temp?

Well if you put it into a fridge, all you are doing is slowing down the process. Cold brew is one of the hardest things to mess up if you ask me, so I would just brew it room temperature. If you extend a brew process in time - than you generally have a larger interval of time where the coffee will still taste great, but since it's already hours long I really wouldn't worry about it. All the shops i've ever worked at brew room temperature. Hope this helps!


When making a long black, how long should hot water cool before adding espresso before combining?

As an American, I've never heard of a long black, but it sounds like a great idea. I normally drink brewed coffee black, but I enjoy an occasional Americano. The only problem is that they're generally served around 400,000° and I can barely hold them and have to wait hours for them to cool down enough to drink. Sometimes I ask for ice or something to cool it quickly. If I just wait for it to cool, it tends to taste rather old and stale by the time I can handle it. Or maybe I just can't taste it because my tongue is crispy from preliminary attempts. But the crema and freshness is always long gone.

I think that must secretly be the real reason for a long black—by adding the espresso to the top of drinkable-temperature water, you still have a chance at the best flavors and aromas. As the Australian coffee roasters Five Senses put it,

  Regardless of the crema, the long black tastes best as it cools slightly from boiling to a drinkable temperature. Only then will you be able to perceive some of the finer nuances and sweetness of the coffee.

So, I would shoot to have the cup around the same temperature as good brewed coffee by the time it hits the drinker's lips. According to Coffee Detective,

  [American-style brewed] coffee is best served at a temperature between 155ºF and 175ºF (70ºC to 80ºC). Most people prefer it towards the higher end, at about 175ºF.

That means, depending on cup type and ambient temperature, if you draw 200°F hot water from the machine before you start making the espresso and leave it uncovered, it will be roughly the right temperature to serve by the time the shots are ready.


How do I get started in roasting my own beans at home?

By far the easiest way to start at home roasting is with a hot air popcorn popper.  You can get a used one for $5 at a thrift store or pay approximately $20 new for one.  Or perhaps you already have an unused one laying around.  There are also people and websites out there showing you great ways to modify or make them better with cheap addon parts or hacks.

I started with one and after I decided I was hooked I spent the money on a commercial made roaster, but I learned most of what I know with a hot air popper in my front yard.  I think the biggest issue for stove top roasting is the smoke.  If you don't have great ventilation in your house over your stove, accidental overroasts and dark roasts become a major problem.


Are there general recommendations for mugs?

Ceramic is more porous than glass, so a ceramic mug insulates better than regular glass and thus keep the coffee hotter, but double-walled glass insulates even better than ceramic.

A porous mug might exchange molecules from one cup to the next. (Is there experimental data on that?)


If I'm in a rush, can I simply use raw ground coffee like instant coffee?

It boils down to taste - some people even chew whole beans.

Safety-wise there are no concerns1 and the method you propose is not unheard of, it goes by the term "Cowboy coffee" and others. Some preparation methods even quickly boil the grounds and water (Turkish coffee), other sources warn against pouring boiling water over your grounds and suggest letting the water cool a few degrees first.

It is up to you to decide whether you like the grainy residue you might taste if you don't let the grounds settle enough before drinking.

So, go ahead and do a taste test. You can always pour your coffee through a sieve or use the leftovers for drip coffee.

1 There is some discussion whether the slightly higher content of coffee oils compared to filtered matters healthwise, but that's a very vague subject, IMHO. Other brewing methods bring more oils as well.


How to preserve crema when pouring a shot into a drink?

This link from Seasoned Advice might help you. The accepted answer recommends to use an espresso brew pitcher and how to use it. The answer suggests two main things:

a vessel with a pour spout helps with retaining the crema;
the speed of the pour is important.

See more information at that link. It suggests that if you pour it in too fast, you ruin the foam. Too slow and the foam gets stuck. Practice sounds important here.


Help me determine the strength of my coffee

The Lungo option is a weaker setting and is still meant to be run ONCE. You run the Lungo option and use a coffee cup slightly larger than the Expresso cup. Nespresso is NOT meant to make a regular cup of coffee ever. It makes Expresso (40ml or 1.4 fluid ounces ounces) or Lungo (110ml or 3.7 fluid ounces). Also not all capsules can be used for Lungo since some are meant for weak Expressos. Get yourself a Coffee Press for regular coffee.

Another Option is make a Lungo and use Expresso to control strength of coffee. So one Lungo and 1 Express will make a medium strength small cup of coffee. Also certain brands like Bustelo capsules make very strong Expresso and Nice Lungo.


How to keep a cup of Coffee hot enough not to burn me?

Did you try a thermos? There are thermally isolated cups. Also, there are many different types of them.

This one, for example, really looks like a miniaturized thermos.

This one is a two-fold stainless-steel cup. Maybe better for camping. The trapped air in between two layers keep your coffee warm for a longer period.

You can also find prettier looking two-fold glass cups. Esthetic ally, they look better.


Do I need higher pressure to create a ristretto?

Typically, a ristretto is an espresso shot pulled with half as much water. If you assume a normal shot is 30ml, the only practical difference in pulling a ristretto is to stop the extraction at 15ml.

The coffee grind, quantity and pull pressure should remain the same.

Regardless, if you feel as if the shot is taking too long, or coming out too fast, you could try adjusting the grind before adjusting the pressure, which should be trickier.


Why does French press not give enough 'Caffeine Effect'?

One of the reasons I like my French Press is because of the caffeine boost. One simple answer to your question is to add more coffee grounds.

But aside from the type and amount of coffee used there are several things that will influence the caffeine level of your coffee. One of them is the size of the ground. You need a ground big enough that it is filtered out but not so big that the water doesn't completely extract the oils and caffeine.

You might try different grind levels and see which one works best.

Another thing you can do is increase steep time. If your grinds are just a bit too large perhaps a 6 minute steep would work better.

You will have to experiment with the grind and steep time.


I would suggest buying any other kind of non-flavored coffee (or borrowing some) and using your same parameters to make a pot.  That should determine whether your machine/process is imparting that taste to the beans or if it's just the coffee itself.

Lightly roasted coffee often has tastes described as woody, grassy, or sometimes tea like.  This can vary from very noticeable at light roast levels to not at all noticeable at moderate levels.  Even if you have purchased those same beans before and were not expecting the taste, it's possible you purchased a bag less roasted than previous bags you have bought.


What is the reasonable size for a coffee ground particle?

You're mis-interpreting the significance of the results in the cited experiment. There were also statistically controlled follow up experiments (e.g. here) that studied grinder particle size distribution in more detail on the same site.

Consequently even when very precise uni-modal particle size regulation is achieved as is the case with industrial roller miller grinders, particle sizes must be deliberately blended for espresso grinds to achieve the required bi-modal distribution.

This bi-modal size distribution is crucial for proper espresso extraction where the coffee bed (espresso puck) is subject to approx 10 bar water pressure.

Your intent in asking for grinder recommendations capable of producing small particle sizes appears to be based on the mistaken assumption that this is the normal working range for grinders. It is not. A good espresso grinder needs to have a well-defined bi-modal distribution with the largest volume of coarse (approx 500u)  and a smaller volume of fine (approx 50u) particles. And a bulk (brewed coffee) grinder should have a tighter unimodal distribution and a working range of about 100 - 1000u.

The first plot above is the particle size distribution by volume in the OP cited experiment showing the characteristic espresso grinder bi-modal curve with average particle size peaks at approximately 500u and 50u. The second graph shows the bi-modal distribution for a Robur espresso grinder from a subsequent experiment (TGPII, Robur). And the third graph shows a high resolution plot from a instrumentation manufacturer (Sympatec).

As to the specific grinders that the OP was considering, all three are well known and respected commercial espresso grinders. FWIW, large conical grinders are easier to use and produce more consistent results. But all would work well for espresso.

Why these things matter

High quality bulk coffee grinders by contrast show a tighter, uni-modal size distribution at the selected size. The usual working range for brewed coffee is about 100u - 900u (Turkish - French press).

  the ground coffee particle size after being placed in water was about
  10 micron (in diameter) on average

10u can only be said to be the average particle size by count. It must be noted however that the proportion of 10u particles by volume is minuscule. A meaningful characterization of average particle size needs to be done by volume or distribution, the former has a strong correlation with expert taste tests.