So what the heck is Tempeh? According to Wikipedia, tempeh is a traditional soy product originally from Indonesia. It is made my a natural, but controlled, fermentation process that binds soybeans together. Whole soybeans are mixed with rice or millets, with a 'starter' culture to begin the fermentation, shaped into flat rectangular cakes and traditionally - these cakes are wrapped in banana leaves and allowed to ferment for 18 to 24 hours before being used in the kitchen.
Lindsay Nixon of Happy Herbivore has a blog posting not too long ago. Because of its nutritional value, tempeh is fast becoming a popular choice as a meat substitute in the diet of strict vegetarians like me. There is some debate over whether or not the bacteria used in the fermentation process produce Vitamin B12 and hence, the Vitamin B12 content of tempeh is a topic for debate too. Because tempeh is made from whole soybeans, it has a high fiber content, but unlike other bean and bean products, the fermentation process breaks down some of the contents making it more digestible, and less gas producing. It is low in sodium unlike some of the other soy products on the market.