Manfred Warmuth, professor of computer science at UC Santa Cruz and probiotic food enthusiast, presents this workshop on making tempeh, a cultured soybean product. In traditional tempeh making, the starter culture often contains other beneficial bacteria that produce vitamins such as B12. In western countries, it is more common to use a pure culture containing only the fungus Rhizopus oligosporus.

See also http://en.wikipedia.org/wiki/Tempeh