Unlike most other foods, MREs do not have an expiration date. Because the shelf life of MREs varies depending on the storage temperature, MRE factories label them with a number that shows the manufacturing date.
But, if the date were in a straightforward day month year format, it would be easy to determine when your MRE is valid. However, that is not the case.
Indeed, when you browse through the sachets, you may see a variety of codes and numbers. It also doesn’t help that the manufacturing date isn’t in a standard place in the package.
The manufacturer code comprises the first and final digits, despite printed as a single number. The first digit reflects the year of manufacture’s final number while the last three digits represent the year’s day out of 365.
Consider the following scenario: you have an MRE with the code 4170. The last number of the MRE’s production year, 2014, would be shown by the four. The 170 would subsequently mean June 19, the 170th day. When you put it together, the MRE’s production date was June 19, 2014.
3365 corresponds to December 31, 2013, whereas 0007 corresponds to January 7, 2010. Because an MRE has a five-year average shelf life, multiply the manufacturer’s year by five to get the estimated expiry date.
One important note is that production dates only show the year’s final number. In the example above, an MRE with 4170 may be from June 19, 2004, or 1994 rather than 2014. When buying MREs, look for other factors such as bag color to indicate when you made the food.
If you buy MREs in bulk, keep a note of the year you purchased them, so you don’t mix up when your items are still good and when they expire due to a misinterpretation of the year date.