Dry Canning Food Preservation Methods

Dry canning, a new term to me, is the art of preserving dry foods and will give them an almost indefinite shelf-life.

Reader Contribution by Lois Hoffman
article image
by Pixabay/lolame

Miss Google is a wonderful asset to gain knowledge on just about anything. However, she can lead you astray, as I found out the other day. When completing any food-preservation project, it is essential to check multiple websites and ensure that each is a reputable source of information. You must be satisfied with your knowledge beyond a shadow of a doubt.

My recent preservation experience started with a YouTube video on dry canning. As one who has always canned many of my own fruits and vegetables, I never thought too much about preserving dry foods. I have always put my flour, cornmeal, and some other dry goods in the freezer, because of the “bugs” that could get into it. The downside to this is that it does take up a lot of freezer space.

So, I was thrilled when I ran across a video on oven canning. I thought I had found a way to be able to buy dry goods in bulk and store them without any of them going bad. However, with a little more research, I found that there are different ways to preserve these dried foods and some were better than others.

Which Foods Can Be Dry Canned?

In a nutshell, “dry-pack canning” is used for foods that have less than 10 percent moisture and are low in oil content. Foods like nuts that contain oils go rancid if kept for long periods of time. Foods such as pasta, cereal, white rice, white flour (unlike brown rice or flour, which contain oils), beans, corn, powdered milk and eggs, herbs and spices and other dried foods are excellent choices for dry canning.

Oxidation is what causes foods to spoil, thus removing oxygen from foods will let them retain their freshness and food quality for long periods of time. Air itself is 78 percent nitrogen, 21 percent oxygen and one percent other gases. Nitrogen does not cause food to spoil.

There are basically three methods of dry canning: oven canning, canning with oxygen absorbers, and food saver jar sealers. It was the oven canning video that caught my attention although that is considered not the safest route to go. Here is what all three entail.

Mason Jars with Oxygen Absorbers

This is by far the safest and easiest method of dry canning. Oxygen absorbers are little packages containing iron powder. When put in airtight containers, oxygen molecules “stick” to the iron. These little packets can reduce the amount of oxygen in containers to less than .01 percent, which is considered safe.

To use, simply put the dry food in a Mason jar or Mylar bag and place the oxygen absorbers on top of the food and seal with lids and rings. It takes approximately 30 minutes for them to absorb the moisture and for the lid to seal. These can also be used with food-grade 5-gallon buckets to store large quantities of food. The thing to remember here is that after the bucket is opened, what food you don’t use must be placed in smaller containers and preserved all over again, because you have let oxygen back in.

Quick transfer. The biggest thing to remember when using oxygen absorbers is to make sure that they are not exposed to the air for any length of time, because they will start absorbing oxygen from the air, rendering them expired in the jars.

Amount. Use enough of them for the amount of food you are preserving. The best rule of thumb is to use enough absorption to deoxygenate the entire empty jar. Usually, 100 cc’s are recommended for pints and 200 cc’s for quarts.

Above all, make sure that they are still good before you use them or your food and time will be wasted. Remember that after the package is opened, they are all exposed. When held in your hand, if they feel like the powder is loose inside them, then they are not expired.

Food-Saving Jar Sealer

The third method is using a Mason jar attachment with your food-saver machine. It seals jar lids to create a vacuum seal that locks air out. This method is considered safe and you do not need oxygen absorbers. If you already have a vacuum sealer, this may be the way to go.

Dry canning does have its advantages and also its drawbacks. On the plus side, you can take advantage of bulk discounts and put away large quantities of dry foods for emergencies and reduce trips to the store. Even though it frees up freezer space, it still requires quite a bit of space elsewhere to store jars and food grade buckets. For example, it takes 24 quart jars to store 50 pounds of rice.

Removing oxygen keeps food from degrading due to oxidation, thus freshness and flavor are preserved for long periods of time. It prevents mold and bacteria from growing in food and kills pests. Dry-canned foods can be stored for 30 years or more as long as the seal remains intact.

Jars should be stored in a dark place where the temperature is below 75 degrees Fahrenheit. A dark cabinet or basement works fine. Many make the mistake of dry canning sugar and salt and there is no need to, because these items are used as food preservatives themselves.

I will definitely be re-arranging my fruit cellar to make room for dry canned goods. I like the idea of always having supplies on hand when needed. Saving money is also a plus! Since I don’t have a vacuum sealer, oxygen absorbers are going to be my go-to.

Dry canning is just one step closer to becoming self-sufficient and who wouldn’t like that.

Lois Hoffman is a freelance writer and photographer covering rural living with more than 20 years of experience, contributing to Successful Farming, Country, and Farm & Ranch Living. She lives on a 37-acre hobby farm in Pennsylvania. 

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