What empirical observation inspired Nicolas Appert's process for preserving solid foods?

Sealing wine in bottles and then heating them

Nicolas Appert, a confectioner without formal scientific training in microbiology, relied heavily on practical observation. His experiments with preservation likely began around 1795. The critical insight came when he noticed that wine, when sealed inside bottles and subsequently subjected to heat (likely through immersion in hot liquid), remained fresh and unspoiled for extended durations. Appert then extrapolated this successful technique—the application of heat to sealed contents—from liquid foodstuffs like wine to solid foods such as meats and vegetables. This empirical discovery formed the basis of his award-winning method, demonstrating the principle of thermal sterilization long before the scientific mechanisms involving microorganisms were understood by figures like Louis Pasteur.