Fermentation of foods

makes foods better digestible; allows better absorption of nutrients and adds some of its own (typically B vitamins)

reduces phytic acid and certain indigestible carbohydrates

can be a way to preserve food for very long times without energy/refrigeration

changes and can improve flavor of food

Lactic Acid Fermentation

The easiest and most common type. Saurkraut as a typical example. Salt and sometime spices are added to reduce activity of bad bacteria (pathogens), mold and yeasts. Best done with a "fido" jar; the co2 that collects in the free space inhibits mold and yeast growth on the surface. Can used used on almost any vegetable, including bean an grain sprouts

Rejuvelac

Lactic Acid fermentation of (sprouted) grains. Vinegar, lemonjuice and raisins can be added to support the fermentation process

Yoghurt

Milkkefir

Waterkefir

Mold based fermentation

Certain molds are harmless to humans an can be applied to food.

koji aka Aspergillus Oryzae makes miso, amazake and sake

Tempeh aka Rhisopus Olysporus

monascus purpureus can be used to make ricewine

white "chinese yeast balls" are likely a variant of koji