Book 9, Question 111
Why Do People Can Food in Jars and Cans?
People can food in jars and cans to keep it safe for a very long time! Heat-sealing kills microbes and blocks new ones from getting in, so the food needs no fridge until it is opened. Home canning needs careful rules and hot equipment, so it is a job for grown-ups.
More fun facts
- Canning works by sealing food in jars or cans and heating them hot enough to kill bacteria and other microbes.
- As the jars or cans cool, a vacuum seal forms that keeps new microbes out.
- Before canning, food could be dried, smoked, fermented or pickled, but none of these were sure to be safe.
- Appert, known as the father of canning, knew his method worked but did not know why.
- In 1943, during World War II, families were urged to can fruit and vegetables from their Victory Gardens in glass top jars to save steel.
Sources: Smithsonian Magazine, National Park Service
Questions kids ask
How does canning keep food safe?
Heat kills the microbes inside, and the vacuum seal keeps new ones from getting in.