How to Preserve Seeds And Grains with Dry Ice

Dry ice helps maintain the post-harvest quality of seeds by controlling insects, bacteria, and fungi which attack stored seeds and grain.

Now that our gardens are in full growth, it’s time to think about storing the yield. Seeds and grains are usually stored after harvest. The seeds will be planted for the next growing season, months away. The grains, which are actually seeds, may be stored for shipping or later processing.

Control of insects in stored seeds with dry ice is done by allowing the dry ice to sublimate into carbon dioxide gas. This CO2 gas is heavier than air, so it will push oxygen out of the storage container, which has a small vent at the top to let the gas escape and avoid a pressure buildup. Without oxygen, CO2 suffocates the insects. Fungi are deactivated at about 50° F and bacteria below about 18% moisture in the air. The dry ice helps provide these conditions in the storage area.

Dry ice can also induce vernalization which is the prolonged exposure to cold temperatures that some seeds require before they will germinate and grow for the following growing season.

If you are interested in saving small amounts of seed of a favorite plant, information about selecting plants and seed saving can be found at www.seedsavers.org, the Seed Savers Exchange. Continental Carbonic Products provides dry ice and liquid CO2 products and product information. Be sure to read the dry ice safety information before beginning your project. How to buy small quantities of dry ice information is here.

Call Continental Carbonic toll-free at 800-DRY-ICE2. Visit our News Archive to find out about more ways to use dry ice. Use your ZIP code to find your closest Continental Carbonic location.