Pickling covers much ground beyond fermentation. Pickles are anything preserved by acidity. Most contemporary pickles are not fermented at all; instead they rely upon highly acidic vinegar (a product of fermentation), usually heated in order to sterilize vegetables, preserving them by destroying rather than cultivating microorganisms. “For pickles, fermentation was the primary means of preservation until the 1940s, when direct acidification and pasteurization of cucumber pickles was introduced,” according to Fred Breidt of the USDA. Vinegar sterilized pickles offer the advantage of not being perishable; however, certain nutrients, including vitamin C, are diminished by heat treatment, and vinegar pickles do not contain the live lactic acid bacteria found in raw fermented pickles.