Food Preservation

Food preservation is one of humanity's most important technologies — enabling food to be stored through winter, transported over long distances, and accumulated as surplus. Before preservation, famine followed harvest failure; after it, civilization became possible. Major methods: drying/smoking (oldest, removes water); salting (osmotic pressure prevents bacterial growth); fermentation (acid and alcohol hostile to pathogens); sugar preservation (jam, candied fruit); pickling; and modern canning (Nicolas Appert, 1809), refrigeration (commercial, 1870s), and freezing. Nicolas Appert invented canning for Napoleon's army — the Emperor offered a prize for a method to preserve food for military campaigns. Clarence Birdseye invented flash freezing in the 1920s after observing Inuit freeze fish instantly in Arctic conditions. Freeze-drying (used for coffee and astronaut food) removes 98% of water while preserving structure. Modern food preservation has allowed year-round availability of seasonal foods globally.