'Pee' soup joins army rations

Next time American soldiers are given pea soup in their rations they might be getting more than they bargained for.

Food scientists have developed a dried food ration that troops can hydrate with.. pee.

The ration comes in a pouch containing a filter that removes 99.9% of bacteria and most toxic chemicals from the water used to make it edible. Besides urine, it can be hydrated using the filthiest of muddy swamp water. The new soldier's chow was invented by the Combat Feeding Directorate, part of the US Army Soldier Systems Center in Natick, Massachusetts.

Two years ago the same organisation came up with the "indestructable sandwich" that stays fresh for three years.

The aim of the exercise is to reduce the amount of water soldiers need to carry, New Scientist magazine reported.

One day's food supply of three meals weighs 3.5 kilograms, but that can be reduced to about 0.4 kilograms with the dehydrated pouches.

Prototype pouches contain chicken and rice. They work by osmosis, the natural way a dilute solution on one side of a semipermeable membrane is drawn to a more concentrated solution on the other side.

Holes in the ration membrane, which is made of thin sheets of cellulose-based plastic, are big enough to let water molecules through but too small for bacteria.