How to use Oxygen Absorbers for Food Storage

Oxygen absorbers are a critical component to successful long term food storage. If used correctly, oxygen absorbers will extend the shelf life of most foods stored with them. Lets dig into oxygen absorbers and learn how to use them for storing food.

Table of Contents

What are oxygen absorbers?

Oxygen absorbers are small packets containing iron powder. They are designed to remove oxygen from the air. Oxygen absorbers come in various sizes to suit whatever size container they will be placed in.

How do oxygen absorbers work?

A chemical reaction occurs when an oxygen absorber is exposed to oxygen in the air. The oxygen molecules adhere to the iron powder thus removing it from the air. This is how they absorb oxygen.

The oxygen absorbers extend the shelf life of foods by removing most of the oxygen from your stored food. The oxygen absorbers will reduce the oxygen level to .01% or less when used correctly.

A byproduct of this chemical reaction is heat. You may notice your oxygen absorber packets will get warm.

Oxygen absorbers do not absorb moisture.

Are oxygen absorbers safe?

While oxygen absorbers are not edible they are relatively safe. The packets contain iron powder and salt. They are completely safe for storing dry foods long term.

Why use an oxygen absorber for long term food storage?

Using an oxygen absorber packet in proper packaging with an airtight seal will dramatically extend the shelf life of many foods.

Removing the oxygen will preserve your foods nutrition, prevent oxidation, protect against mold and bacteria, and kill any insects inside the packaging.

What containers work best with oxygen absorbers?

Oxygen absorbers should only be used in containers with an airtight seal.

Mylar bags – Sealed mylar bags are not only airtight but also protect against moisture and light. You can also use this with vacuum sealing.

Glass jars – With the correct lid a mason jar or other canning jars will have an airtight seal and work well with oxygen absorbers.

#10 cans – Many commercial freeze dried foods are sold in #10 cans. They are airtight containers and if you have the means to seal them, they work well.

Other containers can work well such as plastic bottles but keep in mind that most plastic is permeable and will allow oxygen to slowly enter the container over time.

How to use oxygen absorbers

It’s really quite simple to use oxygen absorbers. All you need to do is place an appropriately sized packet in your containers prior to sealing them. In a matter of hours your food will essentially be packaged in an oxygen free environment.

Make sure you’re using new, fresh oxygen absorbers. They can only absorb a finite amount of oxygen. Once they have absorbed their maximum amount of oxygen they are useless and should be thrown out.

You must use the correct size oxygen absorber packets to remove all the oxygen from your container.

If your oxygen absorbers are hard or discolored it is a good indication that they are expired. They should be soft and malleable

How many oxygen absorbers should I use?

The size of container and type of food you’re storing will determine how much oxygen is present. Based on this information you can determine how many or what size oxygen absorbers to use.

For larger containers I like to use multiple smaller oxygen absorbers instead of one big one. This way you can spread them throughout the food for complete coverage.

The table below gives you a general idea about how much oxygen absorbers are needed depending on the type of food and size of the container. Foods with less air volume typically don’t need as many oxygen abosorbers.

You cannot use too many oxygen absorbers. If in doubt, use more.

Food Type	1 quart	1 gallon	5 gallon
Whole grains	125cc	625cc	2500cc
Rice	100cc	400cc	2000cc
Beans	150cc	600cc	3000cc
Flour	100cc	400cc	2000cc
Pasta	125cc	625cc	2500cc
Powdered milk	100cc	400cc	2000cc

Can I extend the shelf life of all foods by using oxygen absorbers?

Not all foods should be stored with oxygen absorbers. Foods that are dry and low in fat are best. A list of common foods to store with oxygen absorbers is below. Check out our post on how to store dry foods using buckets.

• Rice

• Whole grains

• Dried beans

• Pasta

• Cereals

• Powdered milk

• Flour

• Freeze dried foods

• Spices

What foods should not be stored with oxygen absorbers?

• Wet foods – Oxygen absorbers should only be used with foods that contain less than 10% moisture content. Foods with higher moisture content are at risk for botulism growth. Botulism bacteria can still grow with nearly no oxygen and you risk botulism poisoning.

• Salt – Using oxygen absorbers when storing salt will result in the salt becoming rock hard.

• Sugar – White granulated sugar will also become rock hard. Brown sugar contains too much moisture to safely store.

• Baking Soda – Leavening ability may be compromised, may clump

• Backing powder – Leavening ability may be compromised, may clump

• Yeast – Leavening ability may be compromised, may clump

• Home dehydrated foods – Most consumer-grade dehydrators are not able to dehydrate foods like fruits and vegetables enough. To safely store dehydrated food it must be under 10% moisture content.

A word on fatty foods

The fats in foods such as nuts, seeds, butter, and other oils can go rancid. Using oxygen absorbers storing nuts or other fatty food will not prevent them from going rancid. The oxygen absorbers will still help protect the food’s from oxidation and other potential contaminants.

In many cases the shelf life of high fat foods will be determined by how long it takes the fats to go rancid more than anything else. Keep your foods cool to help prevent the fat from going rancid.

Shelf life expectations

By incorporating oxygen absorbers in your food storage regime it can dramatically improve the shelf life. Your long term food storage will have the best shelf life if you’re also using appropriately seal airtight containers.

Foods	Shelf Life
White rice	10-30 years
Legumes	20+ years
Flour	10+ years
Pasta	20-30 years
Powdered milk	10+ years
Freeze dried fruits and vegetables	25 years
Whole grains	8+ years
Commercially dehydrated fruits and vegetables	10+ years
Potato flakes	30 years
Nuts	1-5 years
Powdered eggs	5-10 years
Corn meal	5-10 years

Do vacuum sealed mylar bags need oxygen absorbers?

If you are vacuum sealing your mylar bags it will remove most of the air but not all. There will be oxygen present and it is wise to still use oxygen absorbers when vacuum sealing.

How do I know my oxygen absorbers are working?

As long as you’re using a new, fresh oxygen absorber you can be fairly confident it will be working. You may notice the oxygen absorber feel warm which is a byproduct of the chemical reaction taking place.

If you’re using mylar bags you may also notice the bags vacuum down a slight amount if they already had a very low air volume. This is because air on earth is about 20% oxygen. It’s subtle though so don’t count on noticing it.

How do I store unused oxygen absorbers?

To keep your oxygen absorbers fresh it is best to store them in a low volume, airtight container that is vacuum sealed. This will prevent them from filling up with oxygen rendering them useless.