A main concern in the development and testing of rations for the U.S. government has always been shelf life. All MRE foods are packaged in triple-layer plastic/aluminum pouches that have better storage qualities than heavy cans, with no need for a can opener. The food in these pouches is precooked and sealed at a high temperature so that bacteria is neutralized. The food then will be shelf stable even when stored at room temperature. Some of the best information available on MRE shelf-life is the storage life chart compiled by the U.S. Army's Natick Research Laboratories. This chart provides a good overview and summary of the findings gathered from their testing of MRE products.
Note: Time and temperature have a cumulative effect. For example, storage at 100° for 11 months then removed to storage at 70° would lose one-half of the 70° storage life. Also avoid fluctuating temperatures, in and out of freezing levels. Due to the cumulative effect of time and temperature, a regular rotation of MRE's within 5 to 7 years is recommended.
More About MRE Shelf Life
- The shelf life ratings shown in the chart on the front of this paper were determined by taste panels -panels of "average" people, mostly office personnel - at the Natick lab. Their opinions were combined to determine when a particular component, or in this case the entire MRE ration, was no longer acceptable.
- The shelf life determinations were made solely on the basis of taste, as it was discovered that acceptable nutritional content and basic product safety would extend way beyond the point where taste degradation would occur. This means the MRE's would be safe and give a high degree of food value long after the timing suggested in the chart.
- MRE pouches have been tested and redesigned where necessary according to standards much stricter than for commercial food. They must be able to stand up to abuse tests such as obstacle course traversal in field clothing pockets; storage outdoors anywhere in the world; shipping under extremely rough circumstances (such as by truck over rocky terrain); 100% survival of parachute drops; 75% survival from free failure drops; severe repetitive vibration (1 hour at G vibration); 7,920 individual pouch drops from 20 inches; and individual pouches being subject to a static load of 200 pounds for three minutes.
- Freezing an MRE retort pouch does not destroy the food inside, but repeated freezing increases the chance that the stretching and stressing of the pouch will cause a break on a layer of the laminated pouch. These pouches are made to withstand 1,000 flexes, but repetitive freezing does increase the failure rate by a small fraction of a percent. Also if MRE food is frozen, then thawed out, it must be used the same as if you had thawed commercial food from your own freezer at home.