<p>The most widely spread collagen material that could do what you want is</p>
<p><strong>Gelatin + glycerin</strong></p>
<p>This is also known as ballistic gel and often used to make molds for chocolate or fondant. For a hard, rubbery consistency mix 2 parts glycerin and 1 part water (by volume), dissolve 2 parts gelatin in it and heat the mixture to melt it. You might want to add an fungizid to avoid mould. Don't boil it.</p>
<p>Alternative recipe for 7,5 liters of a long-lasting ballistic gel by the German channel <a href="https://youtu.be/mlBp9YPiVhM" rel="nofollow noreferrer">Hunting-Gear</a></p>
<blockquote>
<ul>
<li>1215 g ground gelatin</li>
<li>3750 ml destilled water</li>
<li>1875 ml glycerin</li>
<li>1875 ml isopropyl alcohol</li>
</ul>
</blockquote>
<p>If you want a softer consistency, add more liquid in the given ratio. The finished mixture can be melted again and again. Gelatin has a yellowish-brown color and is translucent, but not transparent. There are some special products that promise a glass-clear gelatin that are worth trying out.</p>
<p>According to several sources this gel can last more than a year when stored in the fridge. If it's sealed in a container the alcohol should be sealed in as well, hindering the growth of mould and bacteria.</p>
<p><a href="https://youtu.be/eVrgxPXr9xU" rel="nofollow noreferrer">Video tutorial on YouTube</a> by Lovecraftforever<br />
<a href="http://www.observationsblog.com/sciencetechnologyexperiments/reusable-molding-material-homemade" rel="nofollow noreferrer">Chemical explanation and a slightly more complicated, weight-based recipe</a> by observationsblog.com</p>
<p><strong>Agar-Agar</strong> also forms a gel, but it has a consistency that I would describe as &quot;brittle&quot;. The worst property of agar gel (for your application) is that microorganisms <em>really</em> like to grow on this stuff. That's why it's used in laboratories as culture medium. I would rule it out for a long-term project.</p>
<p><strong>Other materials</strong></p>
<p>In &quot;molecular kitchen&quot; settings we also find sodium alginate, which forms a gel shell around a liquid. I'm not sure you could even create a big, uniform block of sodium alginate gel, though.</p>
<p>Iota Carrageenan and Kappa Carrageenan are usually used in the kitchen to gel dairy products. Iota Carrageenan forms elastic gels like gelatine, but Kappa Carrageenan forms a brittle gel like Agar-Agar.</p>
<p>Methylcellulose only forms a gel when heated and returns to a liquid state when it cools down.</p>
<p>There are collagens of diverse sources that are usually only used in laboratory settings. The technical term is &quot;collagen hydrogel&quot; and it seems to be a field of study on it's own. I'm not sure how applicable these materials are for your scenario, but you'll get a ton of results when searching for it.</p>
<p><a href="https://www.amazingfoodmadeeasy.com/info/modernist-techniques/more/gelification-technique" rel="nofollow noreferrer">An interesting list of food-grade gels</a> can be found in the Amazing Food Made Easy blog.</p>

CC BY-SA 4.0
2023-08-08T09:37:41.443Z
2023-08-09T05:57:54.867Z
2023-08-09T05:57:54.867Z
Elmy
<p>I am wondering if collagen / agar gelatin can be used as an inexpensive material to suspend objects in, like casting rubber. In the application I have in mind the gelatin will in a fully sealed container, not exposed to air.</p>
<p>Will gelatin decay under these conditions? Is there a difference between the collagen and agar in this regard that would make one a better option than the other?</p>
<p>Thanks!</p>

<material-selection><preservation><casting>
Does collagen / agar gelatin decay if not exposed to air?
Emmett Palaima
# Does collagen / agar gelatin decay if not exposed to air?

(Asked by: username_0 on 2023-08-07)

I am wondering if collagen / agar gelatin can be used as an inexpensive material to suspend objects in, like casting rubber. In the application I have in mind the gelatin will in a fully sealed container, not exposed to air.

Will gelatin decay under these conditions? Is there a difference between the collagen and agar in this regard that would make one a better option than the other?

Thanks!

**Tags:** material-selection, preservation, casting


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## 1 answers

### Answer by username_1 on 2023-08-08. Score: 2

The most widely spread collagen material that could do what you want is

**Gelatin + glycerin**

This is also known as ballistic gel and often used to make molds for chocolate or fondant. For a hard, rubbery consistency mix 2 parts glycerin and 1 part water (by volume), dissolve 2 parts gelatin in it and heat the mixture to melt it. You might want to add an fungizid to avoid mould. Don't boil it.

Alternative recipe for 7,5 liters of a long-lasting ballistic gel by the German channel [Hunting-Gear](https://youtu.be/mlBp9YPiVhM)

> * 1215 g ground gelatin
> * 3750 ml destilled water
> * 1875 ml glycerin
> * 1875 ml isopropyl alcohol

If you want a softer consistency, add more liquid in the given ratio. The finished mixture can be melted again and again. Gelatin has a yellowish-brown color and is translucent, but not transparent. There are some special products that promise a glass-clear gelatin that are worth trying out.

According to several sources this gel can last more than a year when stored in the fridge. If it's sealed in a container the alcohol should be sealed in as well, hindering the growth of mould and bacteria.

[Video tutorial on YouTube](https://youtu.be/eVrgxPXr9xU) by Lovecraftforever  
[Chemical explanation and a slightly more complicated, weight-based recipe](http://www.observationsblog.com/sciencetechnologyexperiments/reusable-molding-material-homemade) by observationsblog.com

**Agar-Agar** also forms a gel, but it has a consistency that I would describe as "brittle". The worst property of agar gel (for your application) is that microorganisms *really* like to grow on this stuff. That's why it's used in laboratories as culture medium. I would rule it out for a long-term project.

**Other materials**

In "molecular kitchen" settings we also find sodium alginate, which forms a gel shell around a liquid. I'm not sure you could even create a big, uniform block of sodium alginate gel, though.

Iota Carrageenan and Kappa Carrageenan are usually used in the kitchen to gel dairy products. Iota Carrageenan forms elastic gels like gelatine, but Kappa Carrageenan forms a brittle gel like Agar-Agar.

Methylcellulose only forms a gel when heated and returns to a liquid state when it cools down.

There are collagens of diverse sources that are usually only used in laboratory settings. The technical term is "collagen hydrogel" and it seems to be a field of study on it's own. I'm not sure how applicable these materials are for your scenario, but you'll get a ton of results when searching for it.

[An interesting list of food-grade gels](https://www.amazingfoodmadeeasy.com/info/modernist-techniques/more/gelification-technique) can be found in the Amazing Food Made Easy blog.


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