Self-heating meal
A self- heating meal is a ready -made meal that is heated by a chemical dissolving process without external heat being supplied by a hotplate or the like. They were first used as food in the army , but are now also available for consumers in stores.
Depending on the manufacturer, the packaging contains a can or a bag with separate chambers that contain water and a chemical substance such as B. contain calcium oxide , which releases heat on contact with water due to an exothermic dissolution process. This heat is enough to heat the dish in about 10–12 minutes. The chemical substance does not come into contact with the meal itself.
The manufacturers use different systems:
- Ordinary drinking water must be poured into the heater .
- An enclosed bag of salt water must be poured into the heater
- A certain point on the bottom of the packaging must be pressed in, then the heating process is initiated.
- Self-heating food can: a double-walled food can in which the meal is in the inner can and in the partition a chemical and a water bag, which has to be pierced with a spike to warm the meal.
The self-heating meals are advertised as emergency rations in the event of a power failure or as suitable food for expeditions . A point of criticism is the fact that in relation to the amount of meals there is a comparatively large amount of waste, which also contains chemicals.
history
Self-heating canned meals have been known since around 1900. They were made for mountaineers and expedition participants. Hiram Bingham reported that he used such meals on his expeditions to Peru in 1909–1915. In 1910, balloonist Alan R. Hawley also mentioned that he had eaten three servings of soup from cans that were self-heating during a balloon ride.
In 1941 a New York Times article said:
“Yesterday, we had our first cup of coffee, our first baked beans and our first spaghetti out of the amazing self-heating cans now being introduced by a department store in Manhattan… There's a fifteen-minute wait while the canned food, enclosed in an outer tin, heats without benefit of gas, electricity, or flame of any sort. This trick is accomplished by a chemical inside the first container, and the action is started when four holes are punched in the bottom. The whole mysterious apparatus is turned upside down for the stipulated number of minutes, then righted, and presto! there is your steaming coffee, or food, all ready to serve. "
“Yesterday we had our first cup of coffee, the first baked beans and the first spaghetti made from those amazing self-heating tins that are now in a supermarket in Manhattan… You have to wait 15 minutes while the food heats up (…) This trick will made possible by a chemical in a container, and the process begins when four holes are poked in the bottom. The whole mysterious apparatus is turned upside down for a few minutes, then turned over again, and presto! There is our steaming coffee or the meal, ready to serve. "
In the following years of World War II , these dishes were reserved for the US military, and from 1947 they were restored to all consumers. Initially, however, they did not establish themselves on the market.
In 2006, self- heating hot drinks again came onto the market in the USA, manufactured by Ontech .