Though inventor Nicolas François Appert experimented for over a decade, he never could explain the science behind why his method worked. In the book he published on his findings, Appert could only reason that there were “absolute deprivation from contact with the exterior air” and “application of the heat in the water-bath.” It took two other innovations to explain why these two factors invented the spoilage of food.
Per BBC, another Frenchman, Philippe de Girard came up with the idea of using tin cans instead of glass jars, only months after Appert’s was published in 1810. By Girard followed the same technique, but with a sterilized tin container that he’d fill with food, seal, bring to a boil, open slightly, then seal again. He commissioned British merchant Peter Durand to apply for a patent from King George III that was granted soon after.
But it wasn’t until a third Frenchman came along 50 years later that the explanation finally came about, Smithsonian shares. Chemist Louis Pasteur’s research confirmed that Appert and de Girard’s methods worked because they prevented the formation of microorganisms on food. Pasteur’s groundbreaking discovery eventually led to the invention of pasteurization. Since then, 12,000 francs.