The retort pouch made shelf-stable food light instead of a heavy can

Soldiers and explorers needed food that kept without refrigeration, but the tin can was heavy, hard to open and its long heat treatment overcooked the contents.

From the 1950s the U.S. Army Natick lab, with Reynolds Metals and Continental Flexible Packaging, developed a flexible retort pouch: a laminate filled and sealed, then sterilized under pressure.

Because the pouch is thin, heat penetrates quickly so the food keeps more of its fresh texture; because it is light and flat, a ration fits more food per kilogram and per truck.

NASA took the technology for space food, and the military built the modern meal-ready-to-eat on it.

Sterilize food in a thin, light pouch instead of a can

A thin package heats through in less time, so the food keeps more flavour and texture.

It is lighter and flatter than a can, cutting freight weight and volume.

Shelf-stable and unbreakable, it needs no cold chain or protective outer case.

It opens easily and can be warmed in the pouch, so it suits ration kits and backpacks.

If you can make the container thinner and lighter, you improve the food and shrink the logistics in one move.

Retort pouches became standard for MREs and grew into commercial packaged meals, soups and pet food, while the same flexible-sterilization idea spread to microwaveable pouches and cartons.