Tempeh Making

Tempeh is a chunky, tender soybean cake, especially popular on the island of Java, Indonesia as a staple source of protein. Tempeh making is a natural culturing and controlled fermentation process that binds whole soybeans, sometimes mixed with other grain such as rice or millet, to form a rich cake with a smoky or nutty flavor.

As in most fermentations of food, tempeh making needs a starter. Tempeh starter is a dried mixture of live Rhizopus spores with substrate, either soybeans or rice. To produce good quality tempeh you need a starter with a very high count of desirable Rhizopus molds and contain no contaminating, coliform or pathogenic bacteria. Tempeh can be produced by two Rhizopus strains: Rhizopus oryzae or Rhizopus oligosporus.

Traditional starter in tempeh making is either a piece of the previous day batch tempeh or one especially made by placing a handful of cooked soybeans inoculated with the previous day batch tempeh between two perforated banana, teakwood or hibiscus leaves, allowing them to incubate for a few days until black spores cover the beans, and finally drying them in the sun. The latter is used by rubbing the leaves above the soybeans to be inoculated. Although this type of tempeh starter can easily be contaminated with other molds or bacteria, the climatic conditions in Indonesia are so ideal for tempeh fermentation that this type of contamination is not known to cause problems. In Western countries, however, tempeh making always use pure cultures to ensure consistent quality and to minimize failed batches.

Tempeh making starts with soaking, de-hulling, and partly cooking the whole soybeans. Soaking is done for 6 to 18 hours. To de-hull and split, the beans are squeezed with kneading motion and rinsed clean with water. In Indonesia, traditional tempeh makers soak the beans in a river and stomping them with their feet in large bamboo woven baskets submerged in the river to de-hull.

Cooking is done for about 30 min or till al dente, then the water is drained off but the heating is continued for a few minutes on medium heat to dry the cooked soybeans. Then they are allowed to cool down to below 35°C before mixing in the starter.

A mild acidulent, usually vinegar, may be added either while soaking or before boiling to lower the pH and create an environment that favors the growth of the tempeh mold over competitors. Spread in thin layer, the beans are fermented for 18 to 36 hours at around 30°C (86°F).

Due to its climate, in Indonesia tempeh making doesn’t need incubators. The inoculated beans is simply buried under a pile of leaves to keep it warm and, if necessary, fanned to cool it off.

In good tempeh, the beans are knitted together by a mat of white mycelia to form a compact cake. Under 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.

You can do your own tempeh making. The starter, you may get it over the internet at http://www.tempeh.info. For 250 g of soybeans you need about 3 table spoons of white vinegar and 1 teaspoon of tempeh starter. Use perforated cling film, or perforate empty milk or juice carton, zip-lock sandwich bags or ordinary plastic bags as the packaging. The holes should be thick (about 0.6 mm in diameter) at a distance of about 1 cm to allow the mould to breathe. Press the mix flat to total thickness of max 3 cm. Place the packed beans in an incubator at 30°C (86°F) or at a warm place for about 36- 48 hours to allow fermentation to take place.

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.

Fermented Soybean Products

Some soy foods are made by fermenting soybeans. In the process soybeans are inoculated with some microbes, mostly done with a starter, to push the process in the desired direction. These fermented soybean products contains higher amounts of calcium and vitamin K2.

There are many fermented soybean products in the Asian, especially East Asian cuisines; miso, tempeh and natto are among the many.

Miso

Miso is a traditional Japanese seasoning produced by fermenting, most typically, soybeans, with salt and the fungus kōjikin, resulting a thick paste used for sauces, spreads, and pickling vegetables or meats. A Japanese soup called Misoshiru use this high in protein, vitamins and minerals fermented soybean product as a mix.

Miso is a source of Lactobacillus acidophilus. This fermented soybean product also contains lecithin, a kind of phospholipid that is effective in the prevention of high blood pressure. Some experts suggest that miso can help treat radiation sickness. However miso contains salt, which is essential to animal life in small amount but may cause a variety of health problems in excess.

Tempeh

Tempeh, or tempe in Javanese, is made by fermenting soybeans with Rhizopus molds strains, Rhizopus oryzae or Rhizopus oligosporus that binds the soybeans into a cake form. This fermented whole soybean product is chunky, tender and is consumed daily in Indonesia as part of the main meal, or as a snack.

Tempeh's fermentation process and its retention of the whole bean give it a high content of protein, which is more digestible, dietary fiber, and vitamins. The Rhizopus culture also greatly reduces oligosaccharides that are associated with gas and indigestion. In traditional tempeh making, the starter culture often contains beneficial bacteria that produce vitamins such as B12. Tempeh is also a generous source of minerals such as calcium and iron. Its nutritional value makes this fermented soybean product used worldwide in vegetarian cuisine, partly as meat analogue; while traditionally it is referred to as “Javanese meat.”

Nattō

Nattō is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. A popular breakfast food, protein-rich nattō, together with miso, formed a vital source of nutrition in feudal Japan. There are also other traditional Bacillus subtilis fermented soybean food products in many other Asian countries.

Nattō contains large amounts of Vitamin K, and a much larger amount of polyamine than any other food. Vitamin K involves in the formation of calcium-binding groups in proteins, assisting the formation of bone and preventing osteoporosis, while polyamine suppresses excessive immune reactions. According to a study, fermented soybean products also contain a very important Vitamin for the skin, PQQ.

Some substances in nattō is said to be good for reducing blood clotting and avoiding thrombosis, as in heart attacks, pulmonary embolism, or strokes. This fermented soybean product may also prevent amyloid-type diseases such as Alzheimer.

Soybean and Its Usages

Soybean is the most widely grown and utilized legume in the world and one of the most well researched, health-promoting foods available today. Containing about 40% on the dry weight-base of protein, 35% of carbohydrate, 20% of oil and about 5% of ash, it is one of the richest and cheapest sources of vegetable protein provided for millions of people, an important source of vegetable oil and also ingredients for hundreds of chemical products.

As an excellent source of protein, economically soybean is the most important bean in the world, the most nutritious and most easily digested food of the bean family. It contains a significant amount of essential amino acids, as well as a high levels of essential fatty acids including omega-3, numerous vitamins and minerals, including magnesium and iron, isoflavones, and fiber. Soy protein is the nutritional equivalent of meat and eggs for human growth and health, and with less saturated fat and cholesterol content, consuming soy protein tends to lower cholesterol levels, while consuming protein from animal sources tends to raise them. Just one cup of soybeans provides 57.2% of the Daily Value for protein for less than 300 calories and only 2.2 grams of saturated fat. Also, because soybean contains no starch, it is a good source of protein for diabetics.

Many processed foods use soybean as the primary ingredient, including many meat and dairy product substitutes, and baby foods. In Asia it is extensively consumed in the forms of soybean milk and tofu, fermented products such as soy sauce, tempeh, natto, and miso, sprouted for use as a salad ingredient or a vegetable and may be eaten roasted as a snack food.

Soybean may reduce the risk of colon cancer, possibly due to the presence of sphingolipids as well as fiber. The fiber in soybean is able to bind to cancer-causing toxins and remove them from the body. It also provides preventative therapy for several other cancers, including breast and prostate cancer. Soybean may also prevent high blood pressure, atherosclerosis, cardiovascular diseases, diabetes and obesity.

However, as with many dietary health claims, there are opposing viewpoints on the health benefits of soybeans. Some negative effects of soybean are reported, including allergic reactions, kidney or gallbladder problems due to measurable amount of oxalates, and thyroid problems. For human consumption, soybean must be cooked with "wet" heat in order to destroy the trypsin inhibitors{serine protease inhibitors}. It is not advisable to eat raw soybeans.

Soybean’s oil can be processed into vegetable oil, margarine, shortening, and vegetarian cheeses. It is also the primary source of bio-diesel in the United States. Industrially, the oil is used as an ingredient in paints, adhesives, fertilizers, sizing for cloth, linoleum backing, insect sprays, and fire extinguisher fluids. Soybean is also used in soap, cosmetics, resins, plastics, inks, crayons, and solvents. Since 2001 it has also been used as fermenting stock in the manufacture of a brand of vodka.