The military’s M.R.E.--the Meal Ready to Eat, or those air-sealed packages full of gummy pastes and freeze-dried dreck that soldiers carry into the field--is getting a much-needed upgrade. But it’s not in the form of better tasting dehydrated foods or better freeze-drying technology. Rather, the U.S. Army has developed the world’s most cutting edge sandwich, the BBC reports, one that can be served fresh after sitting on the shelf for a full two years.
When food breaks down--when it rots--it does so as a result of various chemical and biological processes. Some of these are inherent in the ingredients themselves, others are caused by bacteria. But almost universally, these processes require water and/or oxygen to transpire. So the Army didn’t need to reinvent the sandwich or its ingredients to create its long-duration lunch items. But they did need to figure out how to make a sandwich that eliminates water and oxygen from the equation.
Perhaps more difficult is keeping oxygen away from the sandwich. To do so, each one is packed in an air-sealed package with an oxygen scavenger--a small packet of iron filings that pulls oxygen from the ambient air and locks it up in a layer of rust. This keeps oxygen away from things like bread, where it could feed a reaction resulting in mold and decay.
Devoid of oxygen and water, a sandwich can last a long time--two years in this case. And, if the BBC video report is to be believed, the grunts seem to like the two-year sandwich.