Tempeh (English pronunciation: /ˈtɛmpeɪ/; Javanese: témpé, IPA: [tempe]), is a traditional soy product originally from Indonesia. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form, similar to a very firm vegetarian burger patty. Tempeh is unique among major traditional soy foods in that it is the only one that did not originate in theSinosphere.
It originated in today's Indonesia, and is especially popular on the island of Java, where it is a staple source of protein. Like tofu, tempeh is made from soybeans, but tempeh is a whole soybean product with different nutritional characteristics and textural qualities.Tempeh's fermentation process and its retention of the whole bean give it a higher content of protein, dietary fiber, and vitamins. It has a firm texture and an earthy flavor which becomes more pronounced as the tempeh ages.Because of its nutritional value, tempeh is used worldwide in vegetarian cuisine; some consider it to be a meat analogue.
HistoryTempeh being sold in Java, early 20th century
Tempeh originated in today's Indonesia, probably on the island of Java. The earliest known reference to tempeh appeared in 1815 in the Serat Centhini [The Book of Centini]. Three detailed, fully documented histories of tempeh, worldwide, have been written, all by Shurtleff and Aoyagi (1985, 1989, and 2001).
Tempeh begins with whole soybeans, which are softened by soaking and dehulled, then partly cooked. Specialty tempehs may be made from other types of beans, wheat, or may include a mixture of beans and whole grains.
A mild acidulent, usually vinegar, may be added in order to lower the pH and create a selective environment that favors the growth of the tempeh mold over competitors. A fermentation starter containing the spores of fungus Rhizopus oligosporus is mixed in. The beans are spread into a thin layer and are allowed to ferment for 24 to 36 hours at a temperature around 30 °C (86 °F). In good tempeh, the beans are knitted together by a mat of white mycelia.
Under conditions of lower temperature, or higher ventilation, gray or black patches of spores may form on the surface—this is not harmful, and should not affect the flavor or quality of the tempeh. This sporulation is normal on fully mature tempeh. A mildammonia smell may accompany good tempeh as it ferments, but it should not be overpowering. In Indonesia, ripe tempeh (two or more days old) is considered a delicacy.
The soy carbohydrates in tempeh become more digestible as a result of the fermentation process. In particular, theoligosaccharides that are associated with gas and indigestion are greatly reduced by the Rhizopus culture. In traditional tempeh making shops, the starter culture often contains beneficial bacteria that produce vitamins such as B12 (though it is uncertain whether this B12 is always present and bio-available). In western countries, it is more common to use a pure culture containing only Rhizopus oligosporus which makes very little B12 and could be missing Klebsiella pneumoniae which has been shown to produce significant levels of B12 analogs in tempeh when present. Whether these analogs are true, bio-available B12, hasn't been thoroughly studied yet. The fermentation process also reduces the Phytic acid in soy [needs citation], which in turn allow the body to absorb all the minerals that soy provides.