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Will Food Decompose In A Vacuum? Lessons From A Body In Space

Will Food Decompose In A Vacuum? Lessons From A Body In Space

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Paul Brown

I’ve been researching active vs. cold composting and the slower decomposition of organic material in an anaerobic environment. This got me to wondering what would happen if there were a complete absence of oxygen. Food can be vacuum sealed, after all. Is it feasible that a vacuum situation in which no oxygen was present would completely halt the decomposition process? I went on a journey to find out.

Does food decompose in a vacuum? The decomposition process is drastically reduced in a vacuum where there is a total absence of oxygen such as in space. However, the food would eventually decompose through a very slow process that could take many years depending on the presence of anaerobic microorganisms and other variables.

Let’s look at the science behind this and how the principles behind it play a role in composting efforts as well as food preservation.

Absence Of Oxygen Prevents Some Organisms But Not All

The general principle behind the concept of food preservation through a vacuuming process revolves around the removal of oxygen which is required for many microorganisms to survive. That is a fancy way of saying that without oxygen, these germs that decompose food can’t live. You will may also hear that compost will stop decomposing if it is not turned.

All of this makes sense on the surface but when we dig a little deeper we learn that there are actually anaerobic microorganisms that can thrive in these no-oxygen environments. One of the most dangerous of these when it comes to food products is Clostridium Botulinum which can cause death or paralysis in very small quantities (source).

The point is, removal of oxygen will prevent some, but not all, microorganisms. It can slow, but not completely stop, the natural decay of organic material.

Decomposition Occurs With Or Without Oxygen

The absence of oxygen in a vacuum would definitely slow the decomposition process but it does not completely stop it. There is a natural deterioration of organic material that occurs once it is no longer actively feeding. Essentially, plants, just like us, are either alive, dying or dead. You can slow the dying process but the end result is still an absence of life.

Will A Body Decompose In Space?

A human body will continue to decompose in the vacuum of space, though the decomposition process can be significantly slowed.

In my studies on this, I ran across an interesting article from the National Science Foundation UC Santa Barbara where they answer the question of whether or not a human body would decompose in space.

There were several variables to consider of course, such as whether or not the body was in a spacesuit, but the bottom line was that decomposition may be slowed by “thousands or even millions of years” given ideal circumstances such as a lack of any heat, anaerobic microorganisms, or lack of a spacesuit where residual oxygen might exist (source). The article goes on to explain that once all oxygen is removed, the decomposition process transitions from respiration to fermentation but it does not stop.

This academic exercise showed that even in the most extreme of circumstances, organic material will continue to decompose, though admittedly at a significantly reduced rate.

Cnet explored this concept as well, theorizing that the body could last for potentially millions of years (source). And so, in those conditions, sure, food could potentially last indefinitely without “decomposing”. But those are conditions that are extremely difficult to replicate here on earth.

But the principles behind this concept are of use when it comes to food preservation and in fact, are put into practice when we vacuum-seal and freeze food.

Is Vacuum Sealing Food Worth It?

If the decomposition process slows but does not completely stop in a vacuum, is vacuum sealing food for storage worth the trouble? The short answer is yes. Although the food is not going to last forever, the decomposition process will be significantly slowed with the absence of oxygen. As a result, food stored in a vacuum-sealed bag or container will last significantly longer than without.

There is also an added benefit of reducing the introduction of moisture through vacuum-sealing. It’s important to note that this only applies to dry foods. In the case of moisture-rich foods, vacuum-sealing can create conditions that are ideal for the growth of dangerous anaerobic bacterium such as botulism (source). Which brings us to our next topic…

The Hazards Of Vacuum-Sealing Food

It’s important not to over-glorify the benefits of slowed decomposition to the point that we ignore common sense. According to the National Center for Home Food Preservation, vacuum-sealing should not be considered a substitute for refrigeration or freezing. They point out that while combining vacuum-sealing with refrigeration or freezing can provide prolonged benefit, it is not a replacement (source).

The University of Minnesota Extension recommends thoroughly washing hands prior to handling food items meant for vacuum-sealing and to ensure that clean utilities are using in the preparation process (source).

Finally, according to the World Health Organization, “ready-to-eat foods in low oxygen-packaging are more frequently involved in cases of foodborne botulism“.

Will Compost Continue To Decompose In An Anaerobic State?

Compost will decompose, albeit at a slower rate, whether you are turning the pile to encourage the mixture to heat up through the process of active composting or just letting it sit and decay naturally (cold composting). You can even bury organic material and it will slowly decompose under the ground.

When compost is in the aerobic state, aerobic microorganisms go to work helping with the decomposition process. The pile heats up as the magic happens. If you take away the oxygen, however, these little creatures cannot survive and will not be part of the process. But the decomposition will continue as a natural condition of aging, lifeless organic material. This is a critical distinction to understand. And since the compost pile is not in a sterile environment, anaerobic organisms will thrive.

Free Downloadable Food Storage Guides

The following guides are free to download courtesy of the credited websites:


You can significantly slow the decomposition of food through vacuum-sealing but it will not completely stop it. Lack of oxygen prevents many microorganisms from participating in breaking it down but the organic material will continue to slowly decay if it is not alive.

You can purchase a vacuum sealer on Amazon to help preserve refrigerated or frozen foods.

Be sure to read our articles on composting to learn how you can create nutrient-rich organic material at home.