Introduction to Long-Term Food Storage
Copyright © August 2, 2021 by Robert Wayne Atkins, P.E.
All Rights Reserved.
The following is Chapter Forty-Four in my book: The Food Book.
Food can be preserved for future consumption using any of the following methods:
- Refrigeration or Freezing: Requires an investment in a cold storage unit and the temperature inside that unit usually depends on the availability of electricity. This option is discussed in chapter 45.
- Canning Jars: Requires an investment in canning equipment and special canning jars and lids. This option is discussed in chapter 46.
- Vacuum Sealing: Requires and investment in a food sealer and special vacuum seal bags. This option is discussed in chapter 47.
- Buried in the Ground: Some root crops can be left in the same ground where they grew. This option is discussed in chapter 48.
- Root Cellar: This is an underground storage room that remains cool all year. It does not freeze in the winter and it does not get too hot during the summer. This option is discussed in chapter 49.
- Drying and Dehydrating: Foods can be dried using the heat of a fire, or the heat of the sun, or the heat of an oven, or using a special food dehydrator. This option is discussed in chapter 50.
- Smoking: Some foods can be smoked to extend their shelf life. This option is discussed in chapter 38 and chapter 41.
Except for options 1 and 4 above, foods that have been preserved for future consumption need to be stored in an environment that is suitable for the long-term storage of food.
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 safely discard the bodies of any dead rodents you find, and replace the old bait with fresh bait.
- Air Movement: 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. 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 have most of the moisture removed from the food. Dry food should be stored inside a suitable container and the oxygen should 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:
- 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 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 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, the correct number of oxygen absorber packets must be used based on the size of the container to properly control oxygen inside that container. Oxygen absorber packets are usually sold several packets per package. When you open a package all the packets immediately begin absorbing oxygen. Therefore you must have your food containers ready to receive those packets immediately or some of your oxygen absorber packets will be wasted.
- Vacuum Sealing: Food can be vacuum sealed in a plastic container or in a vacuum storage bag. Since all the oxygen will be removed, oxygen absorber packets will not be needed.
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.
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. Eliminating the oxygen minimizes 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:
| Temperature | Shelf Life |
| 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 read the fine print 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.
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Chapter 44 in The Food Book contains a total of 8 pages.
The above information is only the first 2.5 pages of the 8 pages in chapter 44.
Grandpappy's e-mail address is: RobertWayneAtkins@hotmail.com