soy.net

resources and information on soy^{(Copyright 2009 soy.net)}

Fresh tempeh at the market, Jakarta, Indonesia.

Tempeh/Tempe is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form. It originated from Indonesia, invented by the Javanese, where it is most popular, although it is common in other parts of Southeast Asia as well, introduced by migrated Javanese. It 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 compared to tofu, as well as firmer texture and stronger flavor. Tofu, however, has a higher concentration of protein per carbohydrates, and is thought to be more versatile in dishes. Because of its nutritional value, tempeh is used worldwide in vegetarian cuisine; some consider it to be a meat analogue. Even long ago before people found and realized the rich nutrition fact of tempeh, tempeh was referred to as “Javanese meat.”

Production

A piece of uncooked tempeh. 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 knit 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 mild ammonia 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.

Nutrition

The soy protein in tempeh becomes more digestible as a result of the fermentation process. In particular, the oligosaccharides that are associated with gas and indigestion are greatly reduced by the Rhizopus culture. In traditional tempeh making shops, 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 Rhizopus oligosporus.

A piece of uncooked tempeh.

Preparation

In the kitchen, tempeh is often prepared by cutting it into pieces, soaking in brine or salty sauce, and then frying. Cooked tempeh can be eaten alone, or used in chili, stir frys, soups, salads, sandwiches, and stews. Recent popular vegan cookbooks, such as Isa Chandra Moskowitz's "Vegan with a Vengeance", have come up with more creative ways of cooking tempeh, using it as a vegetarian substitution for breakfast meats, such as sausage and bacon. Tempeh has a complex flavor that has been described as nutty, meaty, and mushroom-like. Tempeh freezes well, and is now commonly available in many western supermarkets as well as in ethnic markets and health food stores. Tempeh performs well in a cheese grater, after which it may be used in the place of ground beef (as in tacos). When thin sliced and deep fried in oil, tempeh obtains a crispy golden crust while maintaining a soft interior - its sponge-like consistency make it suitable for marinades. Dried tempeh (whether cooked or raw) provides an excellent stew base for backpackers. While some claim that tempeh should not be eaten raw, others have done so without ill effect for many years. For the Thanksgiving holiday, tempeh (as dark meat) and tofu (as white) may each be thick-sliced and baked with a standard dressing/stuffing preparation to provide a vegan alternative to turkey.

Some cooked tempeh.
 

Types of tempeh

Tempe bongkrèk

Tempe bongkrèk is a variety of tempeh from Central Java, notably Banyumas regency, that is prepared with coconut. This type of tempeh occasionally gets contaminated with the bacterium Burkholderia cocovenenans, and the unwanted organism produces toxins (Bongkrek acid and toxoflavin) from the coconut, besides killing off the Rhizopus fungus due to the antibiotic activity of bongkrek acid.

Fatalities from contaminated tempe bongkrèk were once common in the area where it was produced.  Thus, the sale of tempeh bongkrèk is prohibited by law nowadays; clandestine manufacture continues however due to the superior culinary value. The problem of contamination is not encountered with bean or grain tempeh, which have a different composition of fatty acids that is not favorable for the growth of B. cocovenenans but encourages growth of Rhizopus instead. When bean or grain tempeh has the proper color, texture and smell, it is a very strong indication that the product is safe. Tempe bongkrèk which is yellow is always highly toxic due to toxoflavin, but tempe bongkrèk with a normal coloration may still contain lethal amounts of bongkrek acid.

Tempe Mendoan

A variation of tempeh cooking method, often found in Purwokerto. The origin of the word 'Mendoan' is from Banyumas regional dialect, which means "to cook instantly in very hot oil", that results in raw and limp cooking.
 

Tempeh Recipe

Time: soak: 12 hours
prep: 2 hours
ferment: 24 hours
Difficulty:
Tempeh is a traditional Indonesian food made from soybeans. It is a fermented food, utilizing a special type of mould that forms a cake. When fresh, tempeh has a nice mushroom-like smell and flavor.
Ingredients
400 grams (14 ounces) dried soybeans
water for soaking the soybeans
water for cooking the soybeans
2 tablespoons cider vinegar
1 teaspoon tempeh starter (or ragi tempe)

Equipment

Pressure cooker or saucepan, at least 3 litres (3 quarts)
Large tray (or trays) for spreading cooked beans on to dry
Banana leaves, zip-lock bags or shallow dishes for incubating the fermenting tempeh
Somewhere warm to incubate the tempeh at about 30-35°C / 86-95°F (e.g. your oven, with the light on) thermometer (optional) for keeping a watch on the temperature of the incubator.

Preparation

Cooked fava beans, inoculated with starter and ready to ferment.

Cover soybeans with water, and soak overnight or at least 12 hours. Remove the hulls (i.e. skins) from the beans by rubbing between both hands (see notes).  Skim off most of the hulls either by washing them away or by using a skimmer or strainer. Some hulls may be left behind without affecting tempeh quality.  Cook beans until just tender, not mushy; undercooked is best for tempeh (see notes).  Drain beans, and spread to dry somewhere with airflow (see notes).  Collect beans into a bowl, and mix in the cider vinegar. This acidifies the beans slightly, inhibiting unwanted spoilage organisms during fermentation.  Sprinkle the tempeh starter over the beans and mix in well (see notes).  Pack the beans loosely into banana leaves, zip-lock bags, or shallow dishes for incubating. Zip-lock bags must be punctured at roughly 1cm / ½ inch intervals to keep oxygen up to the fermenting beans.

Fermentation

Load the soon-to-be tempeh into your incubator, preferably on racks that will allow air circulation. An electric oven with a light on makes a pretty good incubator, because the light provides just enough heat to keep the beans warm while the fermentation starts happening. Incubate for 12 hours or so at around 30-35°C / 86-95°F with a heat source (unless it's already that hot where you are). After 12 hours, remove or turn off the heat source - the fermenting beans will be making their own heat, and may overheat if you keep them too warm.  Monitor periodically from then on, and remove when the beans are totally consumed by fluffy white tempeh with no gaps. After fermentation is complete, serve straight away in your favorite tempeh recipe, refrigerate for two to three days, or freeze for up to two months.

Notes, tips, and variations

Fresh tempeh at market, Jakarta, Indonesia Tempeh can be made from almost any legume (beans, chickpeas, split peas), most grains, and some nuts. Tempeh can also be made from okara, the presscake left over from making soy milk and tofu. In Indonesia, this is called tempe gembus. There are many ways to remove the hulls or skins from the beans, including: cracking dried beans in a grain mill and winnowing to remove hulls, grinding soaked beans in hands, rubbing soaked beans between both hands, rubbing cooked beans between both hands (but don't get burnt!), buy them pre-hulled - e.g. chana dal, split fava beans, split peas.  Soybeans can be cooked easily in a pressure cooker at 15psi for 10 minutes with slow-release method, or on a rolling boil for 30 minutes in a saucepan. Soft, ready-to-eat soybeans are not the target here, so don't cook too long.  It can be difficult to distribute the teaspoonful of tempeh starter through the beans evenly. To make the job a little easier, mix the tempeh starter into a couple of tablespoons of rice flour first, then sprinkle and stir this mixture into the beans a little at a time.

References

Shurtleff, William, and Akiko Aoyagi. 1979. The book of tempeh: A super soyfood from Indonesia. New York: Harper & Row (Colophon Books). ISBN 0-06-091265-0.
Shurtleff, William, and Akiko Aoyagi. 1985. The book of tempeh. Berkeley, California: Ten Speed Press.
Shurtleff, William, and Akiko Aoyagi. 1985. History of tempeh: A fermented soyfood from Indonesia. 2nd ed. Lafayette, California: Soyfoods Center. ISBN 0-933332-21-1.
Shurtleff, William, and Akiko Aoyagi. 1989. Bibliography of tempeh and tempeh products: 1,416 references from 1815 to 1989. Lafayette, California: Soyfoods Center. ISBN 0-933332-47-5.

• How We Make and Eat Tempeh Down on The Farm - Mother Earth News, Issue # 47 - September/October 1977
• Yahoo! group dedicated to making tempeh

Sourced from wikipedia.org