Food or beverage made by harnessing the growth of microorganisms. Every fermented food has both a substrate (the item being fermented) and live microbes that feed on the substrate while transforming it into something different. Fermented foods (including vegetable, fruit, dairy, and meat substrates) have been consumed for thousands of years in cultures around the world.

You probably know this as foods like sourdough, kimchi, yogurt, sauerkraut, miso, or beverages like kombucha.

Fun fact: humans have been fermenting food since the Neolithic times. The earliest types were beer, wine, and leavened bread and cheeses. These were followed by the pickling vegetables and fermentation of milk products in East Asia. In many cases, fermentation was accidental, if not serendipitous. In fact, many of these early societies had no idea what caused the sudden, dramatic change to these food substrates and often attributed it to divine intervention—the Egyptians praised Osiris for beer brewing and at many early Japanese miso and shoyu breweries, workers bowed to a shrine daily. We now know that we can thank invisible microorganisms for these delicious and often nutritious things.