Long-Term Food Storage
Copyright © September 9, 2013 by Robert Wayne Atkins, P.E.
All Rights Reserved.
A Suitable Environment for Long-Term Food Storage
The following variables have a direct impact on how long food can be stored before it becomes unacceptable for human consumption:
- Rodents: Rodents can seriously damage or destroy a family's emergency food supplies. Therefore some reasonable method of rodent control should be used in the food storage area. If you use baited mouse traps and rat traps then you should check those traps on a regular basis and replace the old bait with fresh bait, and safely discard the bodies of any rodents that may have been killed.
- Air Movement: Your food containers should be stacked so air can circulate between the stacks of food. Food containers should not be placed in direct contact with the floor or with the walls in the storage area. This is especially true if the area has a cement floor. Food storage containers should be stacked on pallets or on boards a little above the floor, and the stacks should be at least one inch from a wall, and each stack should be one inch from another stack of food. This will permit the normal circulation of air between the stacks of food. This will minimize moisture absorption from the floor or wall, and it will minimize heat gain through the floor or wall.
- Light: Food should be stored in a dark area in the absence of artificial light and sunlight, except when you are in the food storage area for brief periods of time. Sunlight should not enter the area where your food is stored. The sun will raise the temperature inside the storage area. If sunshine makes contact with your food storage containers then the sun will heat the containers and this will reduce the shelf life of the food inside the containers.
- Moisture: Some canned foods are packed in water. Water packed canned foods can be stored for several years and they will still be safe to eat. On the other hand, dry foods should have had most of the moisture removed from the food before it is put in storage. Then the dry food should be stored inside a suitable container and the oxygen should then be removed from that container.
- Oxygen: Oxygen reduces the shelf life of food. There are four ways that oxygen can be removed from a food storage container:
The food storage container must have a lid (or vacuum seal) that forms an air tight seal with the container so fresh air cannot enter the container and cause spoilage.
- Nitrogen: Some commercially packed long-term storage food is inside a container that is filled with nitrogen instead of air.
- Carbon Dioxide: Dry ice can be placed in the bottom of a food storage bucket, and then the dry food can be placed on top of the dry ice in the bucket. As the dry ice gradually evaporates it releases carbon dioxide and drives the air out of the bucket. Then the lid can be placed on the bucket. If you use dry ice then you should also place at least one oxygen absorber packet in the top of the container before you seal the container.
- Oxygen Absorber Packets: Oxygen absorber packets can be placed on top of the food in a food storage container before it is sealed. The packets will absorb most of the oxygen inside the container. However, you must use the correct number of oxygen absorber packets based on the size of the food storage container in order to properly control the oxygen inside that container. Oxygen absorber packets are usually sold with several packets per package. As soon as you open the package all the oxygen absorber packets immediately begin absorbing oxygen. Therefore you will need to have your food containers ready to receive those packets immediately or some of your oxygen absorber packets will be wasted.
- Vacuum Sealing: The food can be vacuum sealed inside a plastic container or inside a vacuum storage bag. Since all the oxygen will be removed from the container you will not need to place an oxygen absorber packet inside the vacuum sealed container.
If any one of the above four methods is used to remove the oxygen then the following benefits will be achieved:
- Any tiny insect eggs that may be present on the food will die due to the lack of oxygen and this will eliminate a potential future insect infestation problem.
- Oxygen and light are the primary causes of food losing its color. Oxygen also causes the oils in some foods to become rancid. Therefore eliminating the oxygen will minimize these two problems.
- The edible shelf life of the food will be significantly extended.
- Temperature: The shelf life of food is significantly impacted by the temperature inside the area where the food is stored. The following table shows the approximate average shelf life of long-term storage food at different storage temperatures:
|40° F (4.4° C)||38 Years|
|50° F (10.0° C)||30 Years|
|60° F (15.5° C)||20 Years|
|70° F (21.1° C)||10 Years|
|80° F (26.7° C)||5 Years|
|90° F (32.2° C)||2.9 Years|
Important Temperature Information: Long-term storage food is normally advertised to last 20 to 30 years in storage. However, if you take the time to read the fine print, then you will discover that the advertised shelf life is based on a specific storage temperature. If you are not able to store your food at the recommended temperature, then your food will not attain the advertised shelf life.
Some Long-Term Food Storage Options
There are a variety of different foods available that will last many years in a reasonable food storage environment. Some of the more common choices include:
Some people find the taste of all of the above foods to be acceptable. But some people find the taste of some of the above foods to be unacceptable. This is a very important issue for you and your family. During hard times when the only food you may have available is the food you have in storage, then that food should be acceptable to the members of your family. The only way you will know whether or not your family will eat and enjoy one or more of the above foods is to actually eat some of that food during normal times. In other woods, purchase a very small sample of one or more of the foods in each of the above categories and then give your family a chance to dine on those foods after the food has been correctly prepared according to the package directions. Listen to what your family says but ask them to be honest and not to object just because it is something they have not tried before. (Note: Under extreme hardship conditions some people will eat anything. However, some people will starve to death if the alternative is to eat a food that they find detestable and if that food makes them nauseous or sick when they are forced to eat it.)
- Meals-Ready-to-Eat or MREs (Individual Meal Packs or IMPs in Canada): An MRE is not dehydrated or freeze dried. An MRE contains moisture and it is a fully cooked meal in one large sealed package for one person. There are several smaller sealed inner packages inside the one large sealed MRE package. The inner packages usually consist of the following: a powdered drink mix (you must supply the water), crackers or bread, peanut butter or jam, cookies or a dessert, main dish, and sometimes a side dish. The largest inner package contains the main dish food item. In most cases it will need to be heated to make it acceptable for human consumption. You can purchase a special MRE heater or you can remove the food item from the package and then heat the food over low heat in a skillet. A single MRE will contain an average of approximately 1,225 calories, along with an ample amount of protein, fat, and carbohydrates. Military MREs are not sold to civilians. The MREs available to the public are special MREs packaged for the consumer market. MREs are usually sold in cases with 12 MREs per case. MREs have the following disadvantages:
Therefore MREs are not a good choice for long-term food storage. However, if you are considering the purchase of some MREs then you should verify the original package date of the MREs, and their current expiration date, or you may purchase some MREs that have already expired, or the MREs may expire in a few months or less. Unlike some other long-term storage foods, MREs do not last very long after their expiration date before they become unacceptable for normal human consumption.
- they are relatively expensive on a per meal basis (usually between $6 to $8 each),
- they have a shelf life of approximately three years,
- their shelf life is significantly reduced if the temperature exceeds 80° Fahrenheit (or 26.7° C),
- the MRE food package can be damaged if it freezes and this may result in the loss of the food inside the package,
- they are relatively heavy,
- they contain a lot of salt, and
- they are very low in fiber and if MREs are eaten over an extended period of time then this will eventually result in constipation.
- Marine Emergency Food Ration Bars: These food bars are high in calories and they are sealed inside a foil package. They are sold in packages of different sizes but the food item inside the package is the same -- there is just more or less of it than in a different size package. Therefore the only difference between packages of the same brand is the total number of calories in one package. These food bars require less storage space inside a backpack than any other type of long-term storage food (on a per calorie basis). These food bars are ready to eat right out of the package. In other words, you do not have to heat the food or add any water to the food to make it edible. However, you will need to drink some water when you eat the food bar in order to facilitate the normal digestive process. There are three major brands available: Datex, Mainstay, and S.O.S. The Datex brand and the S.O.S. brand are both coconut flavored and both brands meet the U.S. Coast Guard standard and the Safety of Life at Sea (SOLAS) standard. The Mainstay brand is lemon butter flavored (similar to the flavor of a lemon butter cookie) and it exceeds the U.S Coast Guard standard and it exceeds the SOLAS standard. The Mainstay brand intentionally has less protein in order to minimize the amount of water required for proper digestion, which is necessary in a marine survival scenario (and this would also be helpful in a hard times disaster scenario). Marine food bars are designed to be edible for at least five years in adverse temperature environments, including extreme high storage temperatures and freezing temperatures. If the food bars are stored in a suitable food storage environment then they will be edible for a lot longer than five years. However, a family could not survive on food bars for an extended period of time. But these food bars can provide nourishment during long hikes when you have to carry everything on your back. The major disadvantage of all three brands of food bars is that they are vacuum sealed inside a foil package and if the foil package is subjected to any significant abrasion during transport then the package may lose its seal. If a food bar package loses its vacuum seal then you will need to consume those food bars within a reasonable period of time, or you can reseal the food bars in your own vacuum storage bag. The table below shows the nutritional data for each of the three food bars. (Note: I have recommended the Mainstay brand food bars since the year 1998 as a reasonable supplement to a family's long-term food storage plan.)
|Protein||6 g||8 g||3 g|
|Cholesterol||2 g||0 g||0 g|
|Carbohydrates||43 g||52 g||46 g|
|Vitamin A||2 %||15 %||50 %|
|Vitamin B6||0 %||0 %||90 %|
|Vitamin B12||0 %||0 %||20 %|
|Vitamin C||2 %||15%||60 %|
|Vitamin D||0 %||0 %||50 %|
|Vitamin E||0 %||0 %||25 %|
|Calcium||0 %||2 %||50 %|
|Folic Acid||0 %||0 %||30 %|
|Iron||0 %||6 %||10 %|
|Magnesium||0 %||0 %||30 %|
|Niacin||8 %||15 %||30 %|
|Pantothenic Acid||0 %||0 %||100 %|
|Phosphorous||0 %||0 %||40 %|
|Riboflavin||10 %||15 %||25 %|
|Thiamine||16 %||25 %||15 %|
- Freeze Dried Food: 98% of the moisture is removed from the food. The food is frozen extremely fast (called flash freezing). While the food is frozen a small amount of heat is applied to the food in a vacuum sealed environment and this removes the moisture content from the food. This process yields food that has almost the same color, flavor, and nutrition as the original food prior to freezing. When the food is rehydrated and prepared for eating, it tastes very similar to fresh food. Therefore many people prefer freeze dried food to dehydrated food. However, freeze drying is a more expensive method of preserving food when compared to dehydrating food. If stored at 70° Fahrenheit (or 21.1° C) then the average shelf life of freeze dried food is approximately 10 years. However, some freeze dried foods have a shorter shelf life and some have a longer shelf life due to the characteristics of the food. (Note: Some food companies state that freeze dried food will last twice as long as dehydrated food, and that freeze dried food weighs a little less than dehydrated food. Since freeze dried food and dehydrated food are both 98% moisture free, I do not know if either of these two claims are true.)
- Dehydrated Food: 98% of the moisture is removed from the food. The food is heated at a very low temperature. This removes the moisture from the food but the temperature is too low to cook the food. This is the process that is used to dry some of the foods that are available at grocery stores, such as dry pasta noodles. If stored at 70° Fahrenheit (or 21.1° C) then the average shelf life of dehydrated food is approximately 10 years. However, some dehydrated foods have a shorter shelf life and some have a longer shelf life due to the characteristics of the food.
- Grocery Store Food: Some of the dry foods in a grocery store have a shelf life of 10 years if they are stored in an environment that is suitable for long-term food storage. The dry foods you may wish to consider are white rice, most dry beans (except kidney beans, lima beans, and soy beans), pasta, powdered milk, oatmeal that does not contain any extra ingredients (either regular or quick), instant potatoes that do not contain any extra ingredients, sugar (granulated, brown, and confectioner's powdered), Kool-Aid drink mix, salt (iodized and non-iodized), black pepper (ground or peppercorns), baking soda, cornstarch, and cream of tartar. In addition to dry foods, many water packed canned foods will be edible for at least five years, such as most vegetables, soups, stews, meat (beef, chicken, pork, and tuna), and honey. If you vacuum seal fresh flour and fresh cornmeal and put them inside a suitable food storage area then they should last at least five years in storage. Do not purchase self-rising flour or self-rising cornmeal because they will not last very long in storage. (Note: You can make your own baking powder whenever you need it by mixing one part baking soda, one part cornstarch, and two parts cream of tartar.) If you currently purchase foods from a grocery store and you enjoy eating those foods, then you may wish to consider some of those foods for your family's long-term food storage plan.
I strongly recommend that you only purchase one container of a food item that you are considering for long-term food storage and that you open it, cook it, and eat it. During the past two years some name brand food companies have significantly altered the food they are now selling. The only way you will be able to determine if the food is still acceptable to your family's taste preferences is to try it now before you buy a huge inventory of that food. For example, I recently purchased a 15 ounce can of Van Camp's Chili with Beans. In the past this brand required a spoon to transfer the contents of the can to a skillet, and after it was properly heated then it tasted like chili should taste, in my opinion. However, when I opened my new can of Van Camp's Chili with Beans I had just purchased, the contents inside the can flowed out of the can into my skillet like a watered down stew. When I looked at the chili in my skillet I was disappointed in what I saw. However, I heated it and I ate it the same way I have always done in the past. While I was eating the chili I was not pleased with its flavor. After I finished eating the chili I had indigestion for approximately three hours. This had never happened to me before with this brand of chili. Needless to say, I will not be purchasing this brand of chili again anytime in the near future.
1. Food should always be stored in food grade containers that are designed for the safe storage of food.
2. Food should always be stored in an environment that is suitable for the long-term storage of food.
Container Sizes for Long-Term Food Storage
Long-term storage foods may be purchased in the following ways:
If you purchase a one-year emergency food supply then you have two options for storing that food:
- Individual Serving or One Meal per Package (dehydrated or freeze dried): The shelf life is somewhere between 7 to 10 years. The nutritional content of the food in one of these packages will be based on the food item in the package. The food package will normally contain between 100 to 750 calories, or an average of approximately 400 calories per package. Since each package only contains one meal, this method can provide a reasonable variety of food because each package can contain a different type of food. The disadvantage of these packages is that they require more total storage space for the same number of calories and they cost more on a per calorie basis. If you are trying to store enough food to last a long time then this option is usually not feasible because it will cost more money and it will require at least three or four times more storage space than the other options that are available.
- Small Cans (dehydrated or freeze dried): These cans contain about 3 cups of food. This size can is a reasonable choice for any food that has a relatively short shelf life after the can is opened, and you do not need the entire contents of one can for one meal. After a can has been opened then the top of the can should be covered with a plastic lid to protect the food remaining in the can from insects and from humidity in the air.
- #10 Cans or 0.83 Gallon Cans (dehydrated or freeze dried): These cans contain between 10 to 12 cups of food. This is a reasonable choice for one person or for two people because an assortment of these canned foods will provide more variety. Several different cans of food can be open at the same time and one or two people will still be able to consume the contents of all the open cans in a reasonable period of time before the food has a chance to go bad. After a can has been opened then the top of the can should be covered with a plastic lid to protect the food remaining in the can from insects and from humidity in the air.
- Six Gallon Pails (or buckets): A six gallon pail contains about 96 cups of food. This is a very good choice for a family of three or more people. The lid on top of the pail can be placed back on top of the pail after you have removed the quantity of food your family will consume in one day.
- 50 Pound Bags: These are sold by weight and the size of the bag will vary based on the food item inside the bag. In other words, 50 pounds of food will weigh 50 pounds but the volume of one type of food (the number of cups) will not be exactly the same as a different type of food. This type of food is usually not packaged for long-term storage. Therefore if you want this food to last for many years then you will need to repackage it yourself inside an oxygen free environment in a more appropriate storage container.
- One-Year Emergency Food Supply for One Person: This food is usually packaged in containers that have a shelf life of ten years in a reasonable food storage environment at 70° F (or 21.1° C). This option appeals to a lot of people because they can make one purchase that includes everything a person will eat for one-year. However, the variety and quality of the food varies considerably based on how much you are willing to pay for a one-year food supply for one person. Some of the one-year food supplies are based on 1,200 calories per day, and some are based on 1,600 calories per day, and some are based on 2,000 calories per day. Some include dehydrated food and some include freeze dried food. The food may be in #10 cans, or in 6 gallon pails, or in a combination of #10 cans and 6 gallon pails. A one-year food supply will normally cost between $1,000 to $4,500 depending on these different factors.
One-year food supplies should be evaluated on the total number of calories and the total quantity of other nutrients in the food. Do not compare the number of cans, or the number of servings, because these are not related to the true value of the food. Some food, such a green beans, have very few calories and very few nutrients. Other foods, such as pasta, have a lot of calories plus a reasonable assortment of other nutrients. Therefore the type of food is more important than the number of cans or the number of servings.
A one-year food supply should have a reasonable variety of food that includes some meat (not textured vegetable protein), some vegetables, some fruit, some dairy items, some wheat or flour, and some other foods necessary for cooking, such as salt and sugar.
If you decide to invest in a one-year supply of dehydrated or freeze dried foods then you should also consider purchasing a special cookbook that is dedicated to these types of food.
- Leave all the cans inside the same boxes in which they were received. In other words, leave all the powdered drink mixes in one box, and all the powdered milk in another box, and all the vegetables in another box, and all the rice in another box, and so on. This would make it extremely easy to keep track of each type of food because you could quickly see how much food is remaining inside each box.
- Rearrange the cans inside the boxes. Each box will hold six cans. You could mix the cans inside a single box so you would have some variety inside each box. In other words, a box may contain one can of powdered milk, one can of rice, one can of meat, one can of vegetables, one can of soup mix, and one can of wheat or flour. This would require more effort to manage your food inventory as you consume your food. However, if you had to quickly evacuate your current location for some reason, and you could not take all your food with you, then you could take as many boxes of food as possible and you would know that you would have a reasonable variety of food in each of those boxes.
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