He was not actually aware that bacteria existed and were the cause of the spoilage. In 1819, Peter Dunrand did the same thing in metal containers he called canisters , from which we get the name can . Drying Microorganisms can't grow well in the absence of moisture. Therefore, taking much of the water out of food will prevent microbes from growing on it. Pasta, grains, dried fruit and flour won't spoil if they are stored in a dry area.
Many microbes are unable to grow when there is high sugar or salt content.
Fruits and jams last longer when sugar is added. Pickles and sauerkraut are preserved by the addition of salt. Salting fish, bacon and ham keeps it from going bad. The pH is a measure of the acidity of something. Examples of things showing a wide range of pH are listed on the next page.