Methods of treating and preserving food products, including a unique method, which avoids undesirable high pressures, additives, or other chemical treatments. The disclosed invention reduces spoilage and undesirable aromas and flavors in fermented food products by killing or reducing the level of wild yeasts and bacteria, and removing oxidants and enzymes without using heat or undesirable additives. The process of the invention uses a combination of moderate pressure and reactive gases, such as carbon dioxide, hydrogen, or nitrous oxide to treat food products, and then removes the reactive gases by purging the food product with an inert gas. The final product is substantially free of unwanted microorganisms, enzymes, and oxidants that cause spoilage of the food product.