<p>It really depends on your budget. You say you are fine with a bit of an investment - how does 2500$ sound?</p>
<p>For that price you can get a <a href="https://new.sca.coffee/entries/lighttells-ca-700-caffeine-cga-analyzer" rel="noreferrer">Lighttells CA-700</a> which lets you analyze the caffeine content in your coffee.</p>
<p>It may sound expensive but compared to the other caffeine testing equipment out there it's relatively cheap.</p>
<p>Depending on how far down the coffee rabbit hole you are, you may have heard of James Hoffmann - he recently <a href="https://www.youtube.com/watch?v=etnMr8oUSDo" rel="noreferrer">made a video</a> about exactly what you are trying to achieve.</p>
<p>I'm afraid this is currently the cheapest method to get reliable, repeatable and somewhat precise results in measuring caffeine content.</p>

CC BY-SA 4.0
2023-01-25T23:46:18.290Z
*Fascinating!* https://patents.google.com/patent/TWI758757B/en and https://www.vidabio.com.tw/index.php give some insight into the way the thing may work; add some reagents, then perform ([electrochemical voltammetry](https://en.wikipedia.org/wiki/Voltammetry)) and send the raw data to (perhaps) your phone for processing. Nice! I've seen claims of roughly +/- 10% with respect to HPLC which would be a substantially larger investment and definitely not backpack-friendly.
uhoh
CC BY-SA 4.0
2023-01-25T22:56:39.093Z
2023-01-25T22:56:39.093Z
technical_difficulty
<p>My experiment began last month.  There were several stalled efforts because I couldn't bring myself to sacrifice my freshly brewed espresso to science.  Eventually I settled on using Starbucks to prepare the coffee, which does seem to offer perhaps an edge in reproducibility.</p>
<p>My aspiration was to use a minimal amount of equipment.  In terms of cost:</p>
<ol>
<li><p>300ml borosilicate beaker ($5.95+tax)</p>
</li>
<li><p>Digital Scale 300 gram Max - 0.01 gram precision ($10.95+tax)</p>
</li>
</ol>
<p><strong>Step 1:</strong> Solid-Liquid Extraction</p>
<p>This is the easy step, fancy nomenclature for brewing coffee as usual.  The beaker fits easily under my espresso machine:</p>
<p><a href="https://i.sstatic.net/nBotzm.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/nBotzm.jpg" alt="brewing espresso into beaker" /></a></p>
<p>I weighed the beaker empty, then weighed it again after adding ~60ml (two shots) of espresso.  (Picture shows my home-brewed double shot just for illustration.  A &quot;store bought&quot; Starbucks doppio was used in actual fact.)</p>
<p><strong>Step 2:</strong> Dehydration of Extract</p>
<p>This is the tedious step, removing the water from the brewed espresso.  I did this as gradually as possible with incremental heating in my 1200w microwave, a few seconds at a time on high followed by blowing over the beaker to remove the water vapor.</p>
<p>As the volume of liquid reduces it is necessary to limit the heating time to mitigate splashes from the boiling of confined solution.  The picture shows that even with a couple of dozen repetitions of just a few seconds, splashing within the beaker occurred.  Indeed a few drops escaped the beaker and landed on the microwave rotating platter, so a better method of dehydration (freeze drying) would be an attractive alternative.  Once the espresso residue was fully dried, I weighed the beaker + dried brown residue.</p>
<p><a href="https://i.sstatic.net/Tm8hzm.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Tm8hzm.jpg" alt="beaker + dried residue" /></a></p>
<p><strong>Step 3:</strong> Sublimation of Caffeine</p>
<p>Once the removal of water appears complete, we take the final step of removing the caffeine that remains.  The key <em>physical chemistry</em> property of caffeine is that its <em>boiling point</em> (352 °F at atmospheric pressure) is lower than its <em>melting point</em> (441 °F or <a href="https://en.wikipedia.org/wiki/Caffeine_(data_page)" rel="nofollow noreferrer">higher</a>).</p>
<p>I preheated my oven (on bake) to 355 °F and put the beaker with the dried residue of espresso on an aluminum pie pan in the oven (center rack).  After a matter of seconds a light gray vapor formed in the beaker. I opened the oven door to allow this vapor to blow away.  After repeating this twice the light gray vapor stopped forming, and I removed the beaker to cool for a final weighing.</p>
<p><strong>Weighings</strong></p>
<div class="s-table-container">
<table class="s-table">
<thead>
<tr>
<th style="text-align: left;">Step</th>
<th style="text-align: right;">Weight (grams)</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left;">empty beaker</td>
<td style="text-align: right;">112.49</td>
</tr>
<tr>
<td style="text-align: left;">espresso</td>
<td style="text-align: right;">161.90</td>
</tr>
<tr>
<td style="text-align: left;">dried residue</td>
<td style="text-align: right;">115.06</td>
</tr>
<tr>
<td style="text-align: left;">sublimated residue</td>
<td style="text-align: right;">114.87</td>
</tr>
</tbody>
</table>
</div>
<p><strong>Conclusion and Notes</strong></p>
<p>The total caffeine present is measured by the difference of the last two weighings, as the weight of caffeine driven out by sublimation.  This figure is 0.19 grams or 190 milligrams plus or minus the scale's precision of 0.01 grams (10 milligrams).  This agrees roughly with the figure of about 150mg cited by <a href="https://www.caffeineinformer.com/caffeine-content/starbucks-double-shot" rel="nofollow noreferrer">CaffeineInformer</a> for caffeine in a Starbucks doppio espresso.</p>
<p>We mention some sources of experimental error besides the 0.01g precision of the affordable Pocket Scale™ pictured below:</p>
<p><a href="https://i.sstatic.net/bdH7am.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/bdH7am.jpg" alt="digital scale" /></a></p>
<p>One source of error, which would tend to reduce both the final residue and the sublimated caffeine, is splatter from the drying process noted earlier.  Another is possible moisture retained after Step 2, which would tend to exaggerate the weight of caffeine by confounding it with water weight.  Also the weight of caffeine we want is small in relation to the weight of the beaker, which presents a subtractive cancellation issue.</p>
<p>In an effort to minimize the effect of these errors, I chose a &quot;single vessel&quot; procedure, so that the relatively small size of the experimental sample is not unduly prejudiced by transfers.  I plan to repeat the experiment and will update if any discrepancies are observed.  In particular after thorough washing the weight of the beaker empty came back to 112.49g.</p>

CC BY-SA 4.0
2023-01-25T05:20:02.847Z
*Interesting!* Hmm... this might be reliable by itself if the dried residue is a mixture of free caffeine and inert, nonvolatile solids (e.g. granite, neutronium, etc.) but I think you need to plot mass vs temperature first and confirm a plateau specific to caffeine and nothing else. https://en.wikipedia.org/wiki/Thermogravimetric_analysis and https://www.hitachi-hightech.com/file/global/pdf/products/science/appli/ana/thermal/application_TA_015e.pdf and https://www.researchgate.net/publication/244749839_Thermoanalytical_study_of_purine_derivatives_compounds
uhoh
CC BY-SA 4.0
2023-01-25T05:44:13.383Z
and  https://www.ijeas.org/download_data/IJEAS0212006.pdf
uhoh
CC BY-SA 4.0
2023-01-27T20:04:27.353Z
Validation of the procedure is relevant.  My thoughts are not so much about a mass vs. temperature plot, although I did gauge the removal of water by reaching a plateau well below the sublimation temperature of caffeine, as to condense the vapor from step 3 and check its purity (caffeine).  I suspect that the cost of additional equipment could be kept below $100, but I didn't want to mix those details in with my basic process write-up.
hardmath
CC BY-SA 4.0
2023-01-27T21:13:49.877Z
That sounds fun!
uhoh
CC BY-SA 4.0
2023-01-28T15:18:49.700Z
There might be other substances that are driven off at the oven temperature. Also, you have poor control over the temperature when you microwave. Using a water bath at a lower temperature and a drying agent to remove the last of the water might work.
Buck Thorn
CC BY-SA 4.0
2023-01-25T04:27:40.287Z
2023-01-25T14:38:05.903Z
2023-01-25T14:38:05.903Z
hardmath
<p>You can get caffeine testing strips that you can dip into coffee☕, and they'll give you an idea of how much caffeine is in the brew.</p>
<p>Here's one brand, D+Caf, but there are some others. They look like this:</p>
<p><img src="https://i.sstatic.net/SGv2d.jpg" alt="Caffeine Test Strips" /></p>
<p>The strips have a couple of lines on them, marked D and C. Decaffeinated beverages will only rise to the D line, caffeinated beverages will rise above it.</p>
<p>You do have the problem of that you're going to have to bust out some science to calibrate this thing yourself—out of the box it will not actually measure the amount of caffeine in a drink, but if you dip it in something that you know has 50mg or 100mg, you can mark repeating lines of that span, to make it a more specific indicator.</p>

CC BY-SA 4.0
2022-12-09T22:33:40.773Z
Thanks! This 2014 comment at the Cooking SE question I link to [Test strips are not available anymore. Starbucks probably made sure of that.](https://cooking.stackexchange.com/questions/1927/how-can-you-measure-the-caffeine-content-of-a-liquid-at-home#comment70852_1928) might still be true; is there any evidence that one can actually purchase "caffeine test trips" in 2022?
uhoh
CC BY-SA 4.0
2022-12-10T01:17:31.627Z
@uhoh, it appears not. I did a search for tests. I couldn't find anything currently available. This 4 yr old Reddit thread talks about all efforts being shut down: https://www.reddit.com/r/conspiracy/comments/ax28ro/all_caffeine_detection_test_strips_manufacturers/. I verified the links. A few products still show up in online catalogs but are listed as unavailable. Caffeine Cop still has a website, but the order-taking is shut off and they abandoned their trademark 11 yrs ago.
fixer1234
CC BY-SA 4.0
2023-01-25T23:18:11.653Z
Have you tried those yourself? How repeatable are the results?
technical_difficulty
CC BY-SA 4.0
2022-12-09T22:27:16.640Z
2022-12-09T22:27:16.640Z
A. Dick Ted
<p>As a consumer of coffee from several different sources (made at home, from a coffee shop, out of a fancy designer can at a convenience store), I have often wondered about their relative caffeine content; &quot;Does three of these equal two of those?&quot;</p>
<p>To that end I'd like to ask if there are any ways that coffee consumers can <em>measure</em> caffeine content of what they are drinking.</p>
<p>I'm not asking if there are tables out there or ways to look some of them up or estimate the caffeine content of these coffees, I'd like to know if there's any way that a particularly nerdy consumer can measure it themselves, even if it requires a bit of an investment.</p>
<hr />
<p>I asked this in Chemistry SE many years ago to no avail:</p>
<ul>
<li><a href="https://chemistry.stackexchange.com/q/70793/16035">Home science optical absorption test for approximate caffeine quantity in coffee?</a></li>
</ul>
<p>Answers here in Cooking SE don't quite make it:</p>
<ul>
<li><a href="https://cooking.stackexchange.com/q/1927/61071">How can you measure the caffeine content of a liquid at home?</a></li>
</ul>
<hr />
<p><strong>update:</strong> Chemistry SE's <a href="https://chemistry.stackexchange.com/q/169318/16035">What is the standard industrial method for measuring caffeine content in food and drinks?</a> has now been nicely answered; just buy a briefcase-sized <a href="https://en.wikipedia.org/wiki/High-performance_liquid_chromatography" rel="nofollow noreferrer">HPLC</a> system with a C18 reversed phase column and a UV detector :-)</p>

CC BY-SA 4.0
2022-11-14T21:14:54.800Z
@tripleee thanks! My spell checker didn't flag that even though "caffein" seems to have lost its battle with "caffeine" almost a century ago :-) https://books.google.com/ngrams/graph?content=caffein%2C+caffeine&year_start=1800&year_end=2019&corpus=26&smoothing=3
uhoh
CC BY-SA 4.0
2022-11-15T05:00:38.537Z
You're most welcome; I was slightly hesitant to propose that change - some people have very specific and sometimes loud opinions about their preferred spellings.
tripleee
CC BY-SA 4.0
2022-11-27T15:34:20.417Z
Unfortunately you can't drink your coffee and measure its caffeine.  Extracting the solutes in a pot of coffee is feasible, and one could weigh them.  This sort of thing has been discussed recently.  Did you want to focus on the expense and time required to do it?
hardmath
CC BY-SA 4.0
2022-11-27T21:52:14.563Z
@hardmath For the purposes of this question I would like to *limit* the expense and time required. A briefcase-sized and properly equipped HPLC system is way to expensive and the corresponding time it would take for someone like me to save up for it is astronomical. But if I could build something and supply it for say a few hundred dollars US for example, I'd be keenly interested! "This sort of thing has been discussed recently..." Where? I'd love to read about it. If there's enough to reference in a partial answer please consider posting one!
uhoh
CC BY-SA 4.0
2022-11-27T23:24:21.233Z
This recent Question, [How can I figure out how much caffeine is in my cup?](https://coffee.stackexchange.com/questions/79/how-can-i-figure-out-how-much-caffeine-is-in-my-cup), drew a range of responses, many focusing on general estimation rather than measurement, but I'd done a bit of research on quantitative approaches.  So maybe I can come up with a post that gives a high-school chemistry take on it.
hardmath
CC BY-SA 4.0
2022-11-27T23:40:12.820Z
@hardmath oh that would be wonderful, thanks!
uhoh
CC BY-SA 4.0
2022-12-03T05:31:45.177Z
https://youtu.be/tiqjf8-yuR4
luser droog
CC BY-SA 4.0
2022-12-03T13:14:23.167Z
@luserdroog espresso metrology - *cool!*
uhoh
CC BY-SA 4.0
2022-12-17T17:50:54.877Z
I have my lab equipment:  a 300 ml beaker and an electronic "pocket scale" with 0.01 gram sensitivity.  My first run (which I could not resist consuming) for proof of concept extracted 32 grams of espresso from 12 grams of coffee grounds.  Cost for equipment was about $18 (including taxes) at a local lab supply shop.
hardmath
<caffeine><equipment>
Are there any ways that coffee consumers can measure the caffeine content of what they are drinking by themselves?
uhoh
# Are there any ways that coffee consumers can measure the caffeine content of what they are drinking by themselves?

(Asked by: username_0 on 2022-11-12)

As a consumer of coffee from several different sources (made at home, from a coffee shop, out of a fancy designer can at a convenience store), I have often wondered about their relative caffeine content; "Does three of these equal two of those?"

To that end I'd like to ask if there are any ways that coffee consumers can *measure* caffeine content of what they are drinking.

I'm not asking if there are tables out there or ways to look some of them up or estimate the caffeine content of these coffees, I'd like to know if there's any way that a particularly nerdy consumer can measure it themselves, even if it requires a bit of an investment.

---

I asked this in Chemistry SE many years ago to no avail:

* [Home science optical absorption test for approximate caffeine quantity in coffee?](https://chemistry.stackexchange.com/q/70793/16035)

Answers here in Cooking SE don't quite make it:

* [How can you measure the caffeine content of a liquid at home?](https://cooking.stackexchange.com/q/1927/61071)

---

**update:** Chemistry SE's [What is the standard industrial method for measuring caffeine content in food and drinks?](https://chemistry.stackexchange.com/q/169318/16035) has now been nicely answered; just buy a briefcase-sized [HPLC](https://en.wikipedia.org/wiki/High-performance_liquid_chromatography) system with a C18 reversed phase column and a UV detector :-)

**Tags:** caffeine, equipment

> **Comments:**
> **username_0**: @username_1 thanks! My spell checker didn't flag that even though "caffein" seems to have lost its battle with "caffeine" almost a century ago :-) https://books.google.com/ngrams/graph?content=caffein%2C+caffeine&year_start=1800&year_end=2019&corpus=26&smoothing=3  
> **username_1**: You're most welcome; I was slightly hesitant to propose that change - some people have very specific and sometimes loud opinions about their preferred spellings.  
> **username_2**: Unfortunately you can't drink your coffee and measure its caffeine.  Extracting the solutes in a pot of coffee is feasible, and one could weigh them.  This sort of thing has been discussed recently.  Did you want to focus on the expense and time required to do it?  
> **username_0**: @username_2 For the purposes of this question I would like to *limit* the expense and time required. A briefcase-sized and properly equipped HPLC system is way to expensive and the corresponding time it would take for someone like me to save up for it is astronomical. But if I could build something and supply it for say a few hundred dollars US for example, I'd be keenly interested! "This sort of thing has been discussed recently..." Where? I'd love to read about it. If there's enough to reference in a partial answer please consider posting one!  
> **username_2**: This recent Question, [How can I figure out how much caffeine is in my cup?](https://coffee.stackexchange.com/questions/79/how-can-i-figure-out-how-much-caffeine-is-in-my-cup), drew a range of responses, many focusing on general estimation rather than measurement, but I'd done a bit of research on quantitative approaches.  So maybe I can come up with a post that gives a high-school chemistry take on it.  
> **username_0**: @username_2 oh that would be wonderful, thanks!  
> **username_3**: https://youtu.be/tiqjf8-yuR4  
> **username_0**: @luserdroog espresso metrology - *cool!*  
> **username_2**: I have my lab equipment:  a 300 ml beaker and an electronic "pocket scale" with 0.01 gram sensitivity.  My first run (which I could not resist consuming) for proof of concept extracted 32 grams of espresso from 12 grams of coffee grounds.  Cost for equipment was about $18 (including taxes) at a local lab supply shop.  

---

## 3 answers

### Answer by username_4 on 2023-01-25. Score: 5

It really depends on your budget. You say you are fine with a bit of an investment - how does 2500$ sound?

For that price you can get a [Lighttells CA-700](https://new.sca.coffee/entries/lighttells-ca-700-caffeine-cga-analyzer) which lets you analyze the caffeine content in your coffee.

It may sound expensive but compared to the other caffeine testing equipment out there it's relatively cheap.

Depending on how far down the coffee rabbit hole you are, you may have heard of James Hoffmann - he recently [made a video](https://www.youtube.com/watch?v=etnMr8oUSDo) about exactly what you are trying to achieve.

I'm afraid this is currently the cheapest method to get reliable, repeatable and somewhat precise results in measuring caffeine content.

> **Comments:**
> **username_0**: *Fascinating!* https://patents.google.com/patent/TWI758757B/en and https://www.vidabio.com.tw/index.php give some insight into the way the thing may work; add some reagents, then perform ([electrochemical voltammetry](https://en.wikipedia.org/wiki/Voltammetry)) and send the raw data to (perhaps) your phone for processing. Nice! I've seen claims of roughly +/- 10% with respect to HPLC which would be a substantially larger investment and definitely not backpack-friendly.  

---

### Answer by username_2 on 2023-01-25. Score: 3

My experiment began last month. There were several stalled efforts because I couldn't bring myself to sacrifice my freshly brewed espresso to science. Eventually I settled on using Starbucks to prepare the coffee, which does seem to offer perhaps an edge in reproducibility.

My aspiration was to use a minimal amount of equipment. In terms of cost:

1. 300ml borosilicate beaker ($5.95+tax)
2. Digital Scale 300 gram Max - 0.01 gram precision ($10.95+tax)

**Step 1:** Solid-Liquid Extraction

This is the easy step, fancy nomenclature for brewing coffee as usual. The beaker fits easily under my espresso machine:

[![brewing espresso into beaker](https://i.sstatic.net/nBotzm.jpg)](https://i.sstatic.net/nBotzm.jpg)

I weighed the beaker empty, then weighed it again after adding ~60ml (two shots) of espresso. (Picture shows my home-brewed double shot just for illustration. A "store bought" Starbucks doppio was used in actual fact.)

**Step 2:** Dehydration of Extract

This is the tedious step, removing the water from the brewed espresso. I did this as gradually as possible with incremental heating in my 1200w microwave, a few seconds at a time on high followed by blowing over the beaker to remove the water vapor.

As the volume of liquid reduces it is necessary to limit the heating time to mitigate splashes from the boiling of confined solution. The picture shows that even with a couple of dozen repetitions of just a few seconds, splashing within the beaker occurred. Indeed a few drops escaped the beaker and landed on the microwave rotating platter, so a better method of dehydration (freeze drying) would be an attractive alternative. Once the espresso residue was fully dried, I weighed the beaker + dried brown residue.

[![beaker + dried residue](https://i.sstatic.net/Tm8hzm.jpg)](https://i.sstatic.net/Tm8hzm.jpg)

**Step 3:** Sublimation of Caffeine

Once the removal of water appears complete, we take the final step of removing the caffeine that remains. The key *physical chemistry* property of caffeine is that its *boiling point* (352 °F at atmospheric pressure) is lower than its *melting point* (441 °F or [higher](https://en.wikipedia.org/wiki/Caffeine_(data_page))).

I preheated my oven (on bake) to 355 °F and put the beaker with the dried residue of espresso on an aluminum pie pan in the oven (center rack). After a matter of seconds a light gray vapor formed in the beaker. I opened the oven door to allow this vapor to blow away. After repeating this twice the light gray vapor stopped forming, and I removed the beaker to cool for a final weighing.

**Weighings**

| Step | Weight (grams) |
| --- | --- |
| empty beaker | 112.49 |
| espresso | 161.90 |
| dried residue | 115.06 |
| sublimated residue | 114.87 |

**Conclusion and Notes**

The total caffeine present is measured by the difference of the last two weighings, as the weight of caffeine driven out by sublimation. This figure is 0.19 grams or 190 milligrams plus or minus the scale's precision of 0.01 grams (10 milligrams). This agrees roughly with the figure of about 150mg cited by [CaffeineInformer](https://www.caffeineinformer.com/caffeine-content/starbucks-double-shot) for caffeine in a Starbucks doppio espresso.

We mention some sources of experimental error besides the 0.01g precision of the affordable Pocket Scale™ pictured below:

[![digital scale](https://i.sstatic.net/bdH7am.jpg)](https://i.sstatic.net/bdH7am.jpg)

One source of error, which would tend to reduce both the final residue and the sublimated caffeine, is splatter from the drying process noted earlier. Another is possible moisture retained after Step 2, which would tend to exaggerate the weight of caffeine by confounding it with water weight. Also the weight of caffeine we want is small in relation to the weight of the beaker, which presents a subtractive cancellation issue.

In an effort to minimize the effect of these errors, I chose a "single vessel" procedure, so that the relatively small size of the experimental sample is not unduly prejudiced by transfers. I plan to repeat the experiment and will update if any discrepancies are observed. In particular after thorough washing the weight of the beaker empty came back to 112.49g.

> **Comments:**
> **username_0**: *Interesting!* Hmm... this might be reliable by itself if the dried residue is a mixture of free caffeine and inert, nonvolatile solids (e.g. granite, neutronium, etc.) but I think you need to plot mass vs temperature first and confirm a plateau specific to caffeine and nothing else. https://en.wikipedia.org/wiki/Thermogravimetric_analysis and https://www.hitachi-hightech.com/file/global/pdf/products/science/appli/ana/thermal/application_TA_015e.pdf and https://www.researchgate.net/publication/244749839_Thermoanalytical_study_of_purine_derivatives_compounds  
> **username_0**: and  https://www.ijeas.org/download_data/IJEAS0212006.pdf  
> **username_2**: Validation of the procedure is relevant.  My thoughts are not so much about a mass vs. temperature plot, although I did gauge the removal of water by reaching a plateau well below the sublimation temperature of caffeine, as to condense the vapor from step 3 and check its purity (caffeine).  I suspect that the cost of additional equipment could be kept below $100, but I didn't want to mix those details in with my basic process write-up.  
> **username_0**: That sounds fun!  
> **username_5**: There might be other substances that are driven off at the oven temperature. Also, you have poor control over the temperature when you microwave. Using a water bath at a lower temperature and a drying agent to remove the last of the water might work.  

---

### Answer by username_6 on 2022-12-09. Score: 3

You can get caffeine testing strips that you can dip into coffee☕, and they'll give you an idea of how much caffeine is in the brew.

Here's one brand, D+Caf, but there are some others. They look like this:

![Caffeine Test Strips](https://i.sstatic.net/SGv2d.jpg)

The strips have a couple of lines on them, marked D and C. Decaffeinated beverages will only rise to the D line, caffeinated beverages will rise above it.

You do have the problem of that you're going to have to bust out some science to calibrate this thing yourself—out of the box it will not actually measure the amount of caffeine in a drink, but if you dip it in something that you know has 50mg or 100mg, you can mark repeating lines of that span, to make it a more specific indicator.

> **Comments:**
> **username_0**: Thanks! This 2014 comment at the Cooking SE question I link to [Test strips are not available anymore. Starbucks probably made sure of that.](https://cooking.stackexchange.com/questions/1927/how-can-you-measure-the-caffeine-content-of-a-liquid-at-home#comment70852_1928) might still be true; is there any evidence that one can actually purchase "caffeine test trips" in 2022?  
> **username_7**: @username_0, it appears not. I did a search for tests. I couldn't find anything currently available. This 4 yr old Reddit thread talks about all efforts being shut down: https://www.reddit.com/r/conspiracy/comments/ax28ro/all_caffeine_detection_test_strips_manufacturers/. I verified the links. A few products still show up in online catalogs but are listed as unavailable. Caffeine Cop still has a website, but the order-taking is shut off and they abandoned their trademark 11 yrs ago.  
> **username_4**: Have you tried those yourself? How repeatable are the results?  

---

