# preserving foods

**URL:** <https://boards.straightdope.com/t/preserving-foods/89133>\
**Category:** Factual Questions\
**Created:** [October 23, 2001, 5:49pm UTC](https://boards.straightdope.com/t/preserving-foods/89133 "2001-10-23T17:49:29Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\
**Post date:** [October 23, 2001, 5:49pm UTC](https://boards.straightdope.com/t/preserving-foods/89133/1 "2001-10-23T17:49:29Z")

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In the process of home preserving food there is a packet of something that is added to dry ingredients that removes oxygen from jars,bags etc. Its used to keep dry beans,peas,flour etc from spoiling when it is desired to keep them for long poriods of time.  
What is that material?  
Where can I purchase it?  
Can I make it myself? How?

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**Author:** ![Ferrous](https://avatars.discourse-cdn.com/v4/letter/f/8e7dd6/32.png) [@Ferrous](https://boards.straightdope.com/u/Ferrous)\
**Post date:** [October 23, 2001, 6:01pm UTC](https://boards.straightdope.com/t/preserving-foods/89133/2 "2001-10-23T18:01:44Z")

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The material is silica gel.

> [@](#):
>
> _From the Encarta Encyclopedia article “Silicon”_  
> Silica gel is a colorless, porous, amorphous substance; it is prepared by removing part of the water from a gelatinous precipitate of silicic acid, SiO[sub]2[/sub]-H[sub]2[/sub]O, which is formed by adding hydrochloric acid to a solution of sodium silicate. Silica gel absorbs water and other substances and is used as a drying and decolorizing agent.

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<div class="post-metadata">

**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\
**Post date:** [October 23, 2001, 6:14pm UTC](https://boards.straightdope.com/t/preserving-foods/89133/3 "2001-10-23T18:14:25Z")

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I believe silica gel removes moisture.  
I want to remove oxygen.

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**Author:** ![Dilbert](https://avatars.discourse-cdn.com/v4/letter/d/58f4c7/32.png) [@Dilbert](https://boards.straightdope.com/u/Dilbert)\
**Post date:** [October 23, 2001, 6:27pm UTC](https://boards.straightdope.com/t/preserving-foods/89133/4 "2001-10-23T18:27:44Z")

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You’re not talking about a vacuum device that pumps the air out? If you aren’t, then I have no idea what you are referring to.

Like this one: [http://www.tilia.com/](http://www.tilia.com/)

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**Author:** ![justwannano](https://avatars.discourse-cdn.com/v4/letter/j/7ab992/32.png) [@justwannano](https://boards.straightdope.com/u/justwannano)\
**Post date:** [October 23, 2001, 7:29pm UTC](https://boards.straightdope.com/t/preserving-foods/89133/5 "2001-10-23T19:29:38Z")

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Not a vacuum device.  
From what I understand the Mormons use an oxygen removing,maybe absorbing or maybe it outgasses an inert gas to drive the oxygen out, packet in their food packaging. Apparently they have their own canning companies.  
I have been advised to get the packets from them but I don’t know where are any of these places.

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**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [October 23, 2001, 8:26pm UTC](https://boards.straightdope.com/t/preserving-foods/89133/6 "2001-10-23T20:26:29Z")

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[Oxygen Absorbers](http://www.google.com/search?hl=en&q=%22oxygen+absorbers%22+food&btnG=Google+Search) for food products  
Some oxygen absorbing packets are made with finely powdered iron. This will rust and remove the oxygen from a closed container. Ascorbic acid, organic dyes, and enzymes are also used in food-grade oxygen removal systems.