<p>I used to think this was just a marketing exercise (when it was applied to crisps/potato chips in American-Speak) but it's to do with it's excellent properties for keeping things fresh and sealing properties.</p>

<p>If we look at the Key features from this <a href="http://www.hydro.com/en/products/Rolled-products/Foil-and-strip-for-packaging/Aseptic-packaging/" rel="nofollow noreferrer">site</a>:</p>

<ul>
<li><p>Aluminium foil in packaging helps keep foodstuffs fresh for months without refrigeration.</p></li>
<li><p>With the outstanding barrier properties and contributions to the sealing process, aluminium foil guarantees the excellent material and filling performance of aseptic and retortable packaging for milk, juices and soups.</p></li>
<li>It prevents the contents from losing nutritional value, vitamins or aroma and gives total protection against light, moisture, oxygen, foreign matter contamination and damage.</li>
</ul>

<p>This is why it's predominantly used in food packaging and not just for coffee packages, the foil is essentially a barrier to the outside environment to stop the beans from being exposed to oxygen and light, although some carbon dioxide gas will build up, there is a relief/degassing valve to allow this to escape</p>

<p><a href="https://i.sstatic.net/H9nAi.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/H9nAi.jpg" alt="enter image description here"></a></p>

CC BY-SA 3.0
2017-04-25T21:30:19.810Z
Light is the main consideration here, I assume. At least, for coffee.
MTSan
CC BY-SA 3.0
2017-04-26T02:45:56.620Z
The main consideration is more likely oxygen - there are plenty of other packaging options that block light, but foil is particularly effective as an oxygen barrier, and "off-the-shelf" coffee has/needs a much longer transit-time/shelf-life than brown-paper-sack local roaster fare. Thus, metal cans or foil bags.
Ecnerwal
CC BY-SA 3.0
2017-04-26T08:09:32.140Z
@Ecnerwal good point will update
EdChum
CC BY-SA 3.0
2017-04-25T15:33:02.517Z
2017-04-26T08:10:30.020Z
2017-04-26T08:10:30.020Z
EdChum
<p>The bags use a Mylar lining that protects from light, oxygen, and moisture.</p>

<p><a href="https://www.sorbentsystems.com/coffee_bags.html" rel="nofollow noreferrer">https://www.sorbentsystems.com/coffee_bags.html</a></p>

CC BY-SA 4.0
2018-11-10T00:18:07.483Z
2018-11-10T00:18:07.483Z
BJ Safdie
<p>Why of-the-shelf coffee packages (available e.g. in supermarkets) are covered with aluminum (or some sort of hard silver a little bit shiny thick foil) from the inside?</p>

<storage><packaging>
Why of the-shelf-coffee packages are aluminum from the inside
Marian Paździoch
# Why of the-shelf-coffee packages are aluminum from the inside

(Asked by: username_0 on 2017-04-25)

Why of-the-shelf coffee packages (available e.g. in supermarkets) are covered with aluminum (or some sort of hard silver a little bit shiny thick foil) from the inside?

**Tags:** storage, packaging


---

## 2 answers

### Answer by username_1 on 2017-04-25. Score: 1

I used to think this was just a marketing exercise (when it was applied to crisps/potato chips in American-Speak) but it's to do with it's excellent properties for keeping things fresh and sealing properties.

If we look at the Key features from this [site](http://www.hydro.com/en/products/Rolled-products/Foil-and-strip-for-packaging/Aseptic-packaging/):

* Aluminium foil in packaging helps keep foodstuffs fresh for months without refrigeration.
* With the outstanding barrier properties and contributions to the sealing process, aluminium foil guarantees the excellent material and filling performance of aseptic and retortable packaging for milk, juices and soups.
* It prevents the contents from losing nutritional value, vitamins or aroma and gives total protection against light, moisture, oxygen, foreign matter contamination and damage.

This is why it's predominantly used in food packaging and not just for coffee packages, the foil is essentially a barrier to the outside environment to stop the beans from being exposed to oxygen and light, although some carbon dioxide gas will build up, there is a relief/degassing valve to allow this to escape

[![enter image description here](https://i.sstatic.net/H9nAi.jpg)](https://i.sstatic.net/H9nAi.jpg)

> **Comments:**
> **username_2**: Light is the main consideration here, I assume. At least, for coffee.  
> **username_3**: The main consideration is more likely oxygen - there are plenty of other packaging options that block light, but foil is particularly effective as an oxygen barrier, and "off-the-shelf" coffee has/needs a much longer transit-time/shelf-life than brown-paper-sack local roaster fare. Thus, metal cans or foil bags.  
> **username_1**: @username_3 good point will update  

---

### Answer by username_4 on 2018-11-10. Score: 0

The bags use a Mylar lining that protects from light, oxygen, and moisture.

<https://www.sorbentsystems.com/coffee_bags.html>


---

