Used correctly, plastic bags are good containers for storing dry food and other items. The following suggestions may help you use plastic bags in your home food storage program.
Only use plastic bags made specifically for storing food. Ordinary garbage bags are not suitable for food storage because they may have been treated chemically to control odors, or they may contain harmful colorings and inks.
Select a bag made of heavy plastic. The sharp ends of some grain kernels will penetrate a thin bag, even if the bag is protected within another container. Using two or more thin plastic bags together can help solve this problem. The thickness of plastic bag material is stated in mils, or thousandths of an inch. A three-mil thickness (.003) should be the minimum for most food storage uses.
For several reasons, small bags are better for storing food than large ones. Once opened, a large bag may be more difficult to reseal, and it may be harder to move. Also, moisture is less likely to build up in smaller bags. Moisture can be a problem even if the items to be stored have been dried, because residual moisture tends to collect on the cooler side of a container. In time, enough moisture can build up to cause the food to spoil. A small bag is much less likely to develop this problem.
Food storage bags must be heat sealed so that they are airtight. No string, tape, or wire binding will adequately seal a plastic bag. Not even bags with interlocking closures will seal tightly enough to keep the contents secure. Special sealing devices that make airtight seams are available. Another way to heat seal a bag is to draw the open end together and bind it with tape, making sure the entire edge of the bag is exposed above the tape. Trim off the edge about one-eighth of an inch above the tape. Then squeeze any excess air from the bag and melt the trimmed edges together with a small propane torch or other suitable heat source.
If you treat grain with dry ice placed at the inside bottom of the plastic storage bag, cushion the dry ice on a layer of grain so the plastic won’t crack or become brittle from the cold. So pressure won’t build up inside the bag, wait until all the dry ice has disappeared before sealing the bag.
Suitably treated water can be stored in large or small plastic bags if the bags are encased in rigid containers. Paper barrels lined with plastic bags have been successfully used for this purpose. To avoid strain on the plastic, bags used as barrel liners should be larger than the barrels.
Usually, items stored in plastic bags must be further protected in secure metal containers. This guards against rodents and makes the items easier to store and stack.
Properly used and reused, plastic bags can be a good addition to a family’s food storage program.—Donald G. Starkey, Dundee, Florida