The food most commonly used for long-term storage is whole wheat berries (Winter wheat) so I will use it as an example. Below is how I do it from start to finish:
I purchase organically grown whole wheat berries (Winter wheat) from a natural foods grocery store that sells in bulk. Whole Foods Market is a national chain that sells bulk foods but there are others including local sources. Rather than buying from the bulk department of the store, I place my order with the store manager and receive my wheat berries in 50 lb bags. They give me a discount of about 10% when I order by the bag. I also purchase other grains and beans for long-term storage in this manner.
I use the same technique to store other items that I buy in bulk, including pinto beans, corn, oats, etc. Most other items will not have the 100 year or longer shelf-life that the wheat berries have. If you start with whole foods that have a very low moisture content, most foods will have at least a 10 year shelf-life when stored in this way. Obviously you should label each bucket with its contents and the date it was sealed. It would also be a good idea to put a “Use by” date on the bucket, in case you forget what the shelf-life is or in case it is opened by someone else.
I order my mylar bags online and they come in many different sizes but I have found that the 20 in x 30 in size is perfect for 5 or 6 gallon food grade buckets. I place the mylar bag in the plastic bucket and fill it with the wheat berries. Then I throw in one 2000 cc oxygen absorbing pack, or two or three of the smaller sized packs, squeeze the excess air out of the bag (or suck it out using a plastic hose) and then seal it with a hot iron. You have to work quickly to avoid overly exposing your oxygen absorbing packs to air, which will decrease their effectiveness. Next I trim off any excess from the top of the mylar bag (optional) and firmly seal the lid on the bucket using a rubber mallet. The wheat berries are now ready for long-term storage in my basement.
Here’s a hint for helping you seal the mylar bags with a hot iron: Take a 30 inch (or 80 cm) 2×4 board and wrap an old towel around it a few times to make an “ironing board.” You can staple or nail the towel on the underside of the board to keep it in place. When you are ready to seal your mylar bag lay this ironing board across the top of the bucket and lay the mylar bag over it to make your job easier (as demonstrated in the photograph above and in the video.) Make sure your seal is complete, and then trim off any excess from the top of the mylar bag. You will have to experiment a little with your iron to determine the ideal temperature. Trim off a small strip from the top of one of your mylar bags and try sealing it with your iron to determine the best setting.
The list below gives the approximate shelf-life for some common bulk items when stored in this manner. These numbers are conservative. It is quite possible that the foods will keep longer. However, all foods lose some of their nutritional value when stored over an extended period of time. The longer they are stored the more nutrition is lost. You should therefore try to rotate these foods out, replacing them with new stock, according to the shelf lifes suggested below. If you open a container and find that the food is moldy, it will most likely be because it contained too much moisture when you sealed it, or else it was exposed to air due to a faulty seal. Throw it in your compost.
If you are wheat intolerant then obviously you will want to store other grains. But keep in mind that most other grains will not have the shelf-life of wheat and so you will need to rotate your stock.
Hard Grains (wheat, corn, kamut millet, dry flax spelt, triticale) 15-20 years
Soft Grains (rolled oats, oat groats, rye, barley, quinoa) 8 years
Rice: White rice will store for 8 – 10 years. Brown rice will only keep for 1-2 years
Beans (soy, adzuki, blackeye, barbanzo, kidney, great northern, lentils, lima, mung, pinto, etc.) 8-10 years
Dehydrated vegetables (broccoli, carrots, celery, cabbage, onions, peppers, potatoes, etc.) 8 – 10 years
Dehydrated fruit 10-15 years
Dried dairy (powdered eggs, powdered milk, whey powder, cheese powder, cocoa powder, powdered butter or margarine) 5-10 years
Flours and ground products (All Purpose Flour, unbleached flour, whole wheat flour, white flour, cornmeal, cracked wheat, gluten, wheat flakes, mixes, etc.) 5 years
Pasta (Macaroni noodles, spaghetti, etc.) 10-15 years
Pure honey, salt, sugar, and sorghum molasses can be kept indefinitely as long as they are kept free from moisture. (Make sure that your honey does not contain additives. Sometimes water or sugar are added to honey. Pure honey will crystallize when stored for a long time. Impure honey will not.)
Garden seeds or sprouting seeds will remain viable for 2-3 years (The exception is alfalfa, which will keep for at least 8 years.)