Wednesday, August 31, 2011
Long-Term Food Storage
When I first started my long-term food storage (decades ago), I tossed wheat in 5-gallon buckets, sealed the lid and walked away. Unfortunately, when I checked some of the buckets years later, I found they were infested with weevils. The containers were tightly sealed, so how did they get in?
Unfortunately, these annoying little beetles deposit their eggs in wheat kernels, which serve as a terrific food source for the hatched larvae. So my weevils came in with the grain. And wheat isn’t the only grain at risk—virtually every grain (including barley, corn, oats, rice, rye) and every food made from grain (yes, noodles included) can be infested.
I’ve learned more about proper storage techniques over the years, so now I store my grains in mylar bags with oxygen absorbers all placed inside tightly-sealed 5- or 6-gallon buckets.
Oxygen absorbers are nifty little packets containing iron powder which absorb oxygen. Removing the oxygen helps extend the shelf life of your stored foods by preventing their oxidation; but more importantly, bugs can’t survive without oxygen (a double bonus). The packets are sealed, so there is no risk to your food items.
To use mylar bags, place one in a bucket and then fill the bag with your grain or other food item. Place the correct number of oxygen absorber packets on top of the food (keep them apart so they don’t touch) and then seal the mylar bag. The mylar bags I purchase require heat sealing. Since I didn’t want to spend money to buy a heat sealer, I simply used a flat iron originally sold for straightening hair. It works great. Finally, place the lid on the bucket and seal. That’s it. Because the oxygen absorbers start absorbing oxygen the minute you remove them from their protective bag, it's important to work quickly and be sure to re-seal the bag (a Food Saver works well) containing any remaining oxygen absorbers.
The number of oxygen absorbers required per bucket will vary depending on the capacity of the absorbers (measured in cc – or cubic centimeters), as well as the volume the bucket will hold, and the type of food you will be storing. Dense foods such as flour require fewer absorbers (because there is less air in the bucket) than do beans and other foods that may have more air in the bucket. USA Emergency Supply has a great chart on their website showing recommended amounts of oxygen absorbers for different foods and various bucket sizes. The photo below shows a 5-gallon bucket of wheat with three 500-cc oxygen absorbers.
You can also use dry ice to fumigate wheat or other grains. To do this, place a few (3-4) inches of grain on the bottom of your bucket. Top this with two or three ounces of crushed dry ice, then finish filling the bucket. Put the lid loosely onto the bucket, but do NOT seal. After the ice has melted (about 30 minutes), seal the bucket. This technique works to kill the weevils because it replaces the oxygen in the bucket with carbon dioxide. I have read several reviews online that say this technique will work just as well if you fill the bucket completely with grain and then place the dry ice on top of the grain. At least this make it easier to tell if the dry ice has completely melted before sealing the bucket. Note: Because dry ice is frozen carbon dioxide, it is significantly colder than ice made with water and can easily cause frostbite if handled incorrectly. Always wear gloves when handling dry ice.