Tempeh

Tempeh, or tempe in Javanese, is a traditional food made by natural culturing and controlled fermentation of soybeans by two strains of Rhizopus molds: Rhizopus oryzae or Rhizopus oligosporus, that cover the beans with their mycelia to form a cake. It is a staple source of protein in Java made from whole soybeans. The retention of the whole bean and the fermentation process give tempeh a higher content of protein, dietary fiber, and vitamins, plus firmer texture and stronger flavor compared to tofu. Its rich nutritional value makes tempeh used worldwide in vegetarian cuisines, partly as meat analogue, while long before it was referred to as “Javanese meat.”

Tempeh is made by soaking, de-hulling, and partly cooking the whole soybeans, and then lowering the pH, usually with vinegar, to create favorable environment, and mixing with fermentation starter containing the spores of the Rhizopus fungus. This mix is then allowed to ferment for 18 to 36 hours at a temperature around 30°C (86°F).

To produce good quality tempeh you need a starter with millions of the Rhizopus spores and contain no contaminating, coliform or pathogenic bacteria. It is often extended with sterile rice flour or starch to standardize the spore count. In Indonesia tempeh starter is either a piece of the previous batch tempeh, or dried starter made by incubating a handful of cooked and inoculated soybeans between two hibiscus leaves for a few days until black spores covering the soybeans and then drying them in the sun. To use the spores, the hibiscus leaves are then rubbed above the soybeans to be inoculated. These types of starters are vulnerable to other molds or bacteria contaminations, but the climatic conditions in Indonesia are so ideal for tempeh fermentation that the contamination is not troublesome. In Western countries pure cultures are used to insure consistent quality and to minimize failed batches.

Tempeh keeps well frozen for several months and refrigerated for about 10 days. As with other fermented products, a little mold on the surface of tempeh is harmless.

Since whole soybeans are used, tempeh is fiber-rich. It is also a generous source of calcium, B-vitamins and iron. Fermentation makes the protein in tempeh more digestible, and the Rhizopus culture greatly reduces the oligosaccharides associated with gas and indigestion. In traditional tempeh making, the starter culture often contains beneficial bacteria that produce B12 vitamin.

Tempeh has a smoky, nutty, meaty, and mushroom-like flavor. In Indonesia it is usually consumed with rice or as a snack. Its tender, chunky and chewy consistency makes it an excellent addition to a variety of foods. Tempeh on the grill is delicious; frozen can be well grated to replace ground beef, as in tacos; fresh is suitable for marinades and deep fried; and dried provides an excellent stew base for backpackers. Tempeh can also be used in chili, stir fry, soups, salads, spaghetti sauces, sandwiches, and casseroles. Vegetarians use it as a substitution for breakfast meats, such as sausage and bacon.