Water is a primary element used in the process of canning. Water canning, or water bath canning, is the process of preserving foods without refrigeration or smoking and curing. Essentially, water canning involves sterilizing all the bacteria in food. The bacteria spoils or infects the food, causing it to go bad.
The process of water canning was invented by the Frenchman Nicholas Appert. Appert responded to a call from Napoleon Bonaparte to find a way to preserve food for his army. “An army travels on it’s stomach,” was a saying by Bonaparte. It took Appert about 15 years to finalize this process. Appert won a large monetary prize for his discovery of the process of canning.
His discovery was actually quite simple in nature. It works like this:
- Seal the food in an air-tight, cookable container.
- Cook the container long enough to destroy the bacteria within the food.
- Because the container is airtight, then the food remains sterile and will keep indefinitely.
Appert utilized a water bath, hence “water bath canning,” in which to cook the cans. Different foods have varying amounts of bacteria. For example, potatoes that are grown in the ground have much more bacteria than green beans, which grow suspended in the air. So, Appert discovered that foods with more bacteria, like potatoes, have to be cooked longer than foods with less bacteria, like green beans.
Appert’s discovery came 100 years before Louis Pasteur proved that bacteria could be killed by heat. Appert used sealed bottles for his work. It was later that another Frenchman added to Appert’s discovery. Peter Durand used sealed tin cans in a similar process. This was called “canning” and the title his stuck, whether food is being preserved in cans or jars.