Do It Yourself Bulk Food Storage: Buckets, Oxygen Absorbers, Desiccants, and CO2

From what I’ve heard letters and e-mails, most SurvivalBlog readers already have a food storage program, but most of them would like to move on to the next step: buying and storing foods in bulk. To save money you will probably want to buy rice, wheat, and beans in 50 pound sacks. Sacks are problematic, since what you really want is a vermin-proof, moisture proof container that is air tight and preferably evacuated of oxygen. Those are the keys to true long term shelf life, and none of them are provided by a cloth, paper, or woven plastic sack. The solution is to re-pack bulk foods in food grade plastic buckets. Here is how to do it:

Food grade five or six gallon bucket with rubber “o-ring” seals are available through a variety of Internet vendors. Be sure to specify “food grade” when you buy. Other buckets intended for products like paint are not safe for use in food storage, even if bought brand new. Although these usually have the same white plastic formulation, they are typically manufactured using a different mold release agent, which is toxic. So don’t buy paint buckets!
Used food grade buckets are often available for free or perhaps a dollar apiece if you ask around at local delicatessens and bakeries. Flour buckets are usually best, since buckets that were used for pickles or peppers might leave you with food that has undesired flavors!

The method that I use is as follows: Line a bucket with a large plastic bag and pour in the wheat, rice, or beans, shaking the bucket and tapping it on the floor several times to get the bag completely full. You don’t want any air gaps. Fill the bag so that the bucket is filled to within one inch of the top. Then toss two Oxygen absorbing packets (available from NitroPak) into the bag. Next, place a small chunk of dry ice on top of the grain, inside the liner bag. I usually use a piece that is about as big as my thumb. As the dry ice “melts” (sublimates) it will fill the bucket with CO2, displacing the oxygen. (Insects can’t breathe CO2!) Keep a watchful eye on the dry ice. Once it has sublimated to the diameter of a nickel and not any thicker than 1/8th inch, seal the bag with a wire twist tie. On top of the sealed bag, place a 2 ounce bag of silica gel desiccant. (Also available from from NitroPak.) Then immediately seal the bucket, securing the lid with firm strikes from a rubber mallet. This will seat the lid and compress the o-ring. WARNING: If you don’t wait until the dry ice has nearly completely sublimated before you seal the bucket, then dangerous pressure could develop. (A “dry ice bomb.”) Again, you must wait until the dry ice chunk has sublimated to the diameter of a nickel, and not any thicker than 1/8th inch. The end result: Very dry food in a sealed, oxygen-free environment, safe from mice. This method will triple or quadruple the shelf like of rice and beans, and make whole grain wheat last literally for decades.
Another method that can be used in place of dry ice is a CO2 probe or “wand”, attached with a hose to a compressed cylinder of CO2 . A complete description of dry ice and CO2 probe methods can be found in Alan T. Hagan’s excellent Food Storage FAQ at Captain Dave’s site.
Once you open each bucket of storage food, you will probably want to replace the standard “pound on” lid with a screw closure “Gamma Seal” lid. These lids have an inset screw top, so that they are more convenient to access for daily use. Gamma Seal lids are available through a number of Internet vendors such as Walton Feed and NitroPak, for around six dollars each. If you want to buy 20 or more lids, you can get them directly from the manufacturer, at www.gammaseals.com.