History of Tempeh - Page 2
by William Shurtleff and Akiko Aoyagi
A Chapter from the Unpublished Manuscript, History of Soybeans and
Soyfoods, 1100 B.C. to the 1980s
©Copyright 2004 Soyfoods Center, Lafayette, California
New Interest in Tempeh (1960-82) Continued
Starting in the late 1960s and early 1970s a number of changes began to take place in the process for making tempeh in Indonesia. The most noticeable of these was the use of polyethylene bags (and, to a more limited extent, wooden trays lined with plastic sheeting) in place of banana leaves as the container in which the tempeh was incubated and sold. These techniques were developed in 1964 by Martinelli and Hesseltine at the USDA/NRRC in Peoria, Illinois. The oldest method for making tempeh inoculum was the sandwiched hibiscus leaf method, in which inoculated soybeans were sandwiched between hibiscus leaves and incubated until the molds sporulated. The finished inoculum was known as laru , waru , or usar . Finally, the spores on the leaves were rubbed over warm soybeans requiring inoculation. In 1895 Prinsen Geerligs reported that kechap ( katjap ) and taucho ( Tao-Tjiong ) were both inoculated with Hibiscus tiliaceus leaves, in Java called "waroe." A sporulated substrate (typically a previous batch of tempeh) was also used. But starting in mid-1960s research began in Indonesia to improve traditional starters. Ko (1964) described an improved soybean-based starter, then in 1967-68 developed and tested a semi-pure culture inoculum based on cooked rice, incubated in aluminum trays, then dried, pulverized, and stored sealed in a cool place. The process required no sophisticated equipment (Rusmin and Ko 1974). Hermana and Roedjito (1971) were the first to publish a method for the use of steamed rice (plus cassava and soy flour) as a tempeh inoculum substrate. By the mid-1970s a pre-prepared rice-based tempeh inoculum started to be used by some larger manufacturers; a key supplier was the Department of Microbiology at Bandung Institute of Technology (Shurtleff and Aoyagi 1979; Jutono 1979; Hartadi 1980). By 1982 tempeh starter was being sold in Indonesian supermarkets.
Traditionally all of the soybeans used to make tempeh were grown domestically; presumably they had been selected over the years for their suitability to tempeh production. But imports of soybeans, largely from the USA, increased dramatically during the 1970s, reaching 156,000 tonnes in 1976 (about 25% of domestic production) then rising to roughly 365,000 tonnes in 1983 (59% of domestic production). US soybeans were larger, cleaner, and about 15-20% less expensive, but the Indonesian soybeans were found (by whom??) to have a higher content of isoflavones, which retards rancidification of the tempeh when it stands at ambient temperatures. Larger manufacturers began to dehull their soybeans with a motor-driven stone mill, then remove the hulls using a semi-automatic flotation device. However, the abundance of low-cost labor and the high cost of fuel, energy, and imported equipment, prevented widespread mechanization of the process. By 1977 a 75-minute color film had been made on tempeh; it was available from the Jakarta Management Institute (Shurtleff & Aoyagi 1979).
The first detailed and comprehensive survey of the tempeh industry in Indonesia was published by Winarno and co-workers in 1976. It reported that, at that time, tempeh was the nation's most popular soyfood, making use of 64% of the country's total soybean production and imports. There were 41,201 tempeh manufacturers, mostly small, family-run enterprises, which made fresh tempeh daily. They employed a total of 128,000 workers, who produced each year 153,895 metric tons of tempeh having a retail value of US$85.5 million. Most companies were small, run out of the home. The largest companies used no more than 100 kg of soybeans a day to make 175 kg (385 lb) of tempeh. (This would be 1,050 kg (2,310 lb) of tempeh per 6-day week.) Tempeh was an important source of high-quality, low-cost protein and vitamins in the diet of all Indonesian socio-economic groups, and especially in the diet of low-income families. Yet its importance should not be exaggerated. Per capita consumption for all Indonesians in 1976 was about 16 gm a day or 5.8 kg (12.8 lb) a year. Tempeh was typically consumed in amounts of 100-200 gm per person per meal. A summary and analysis of Winarno's findings on the Indonesian tempeh industry is given in the professional edition of The Book of Tempeh (1979) by Shurtleff and Aoyagi.
The remarkable versatility of the tempeh fermentation process allows the preparation of many different types. Traditionally in Indonesia the great majority of all tempeh was soy tempeh ( témpé kedelé ) and by the mid-1970s it constituted an estimated 90% of all tempeh produced. Well-known varieties of soy tempeh included thick Malang tempeh and one-bean-thick Purwokerto tempeh. Other traditional types of tempeh included: okara tempeh ( tempe gembus or onchom hitau ; Gandjar and Slamet 1972; Gandjar 1977), soybean-hulls tempeh ( tempe mata kedele ; Gandjar and Hermana 1972), peanut presscake tempeh ( onchom hitam ; van Veen et al. 1968), the occasionally poisonous coconut presscake tempeh ( tempe bongkrek ; van Veen 1950-73; Harsono 1970; Gandjar and Hermana 1972; Arbianto 1977), velvet-bean tempeh ( tempe benguk ; Gandjar 1977), leucaena tempeh ( tempe lamtoro ), mung bean tempeh ( tempe kacang hijau ), mung bean pulp tempeh (Gandjar 1977), plus several other minor varieties (Vorderman 1902; Ko and Hesseltine 1979; Shurtleff and Aoyagi 1979). The okara tempeh, presscake tempehs, and other non-soy tempehs were consumed more by lower-income groups. Starting in the late 1970s, however, the use of new seeds and grains for tempeh-making began to be investigated. Gandjar (1977, 1978) did several studies on winged bean tempeh. Tanuwidjaja (1977) studied the fortification of low-cost presscake tempehs with soy flour to improve the diets of the very poor. And bulgur wheat was reported to be mixed with soybeans to make tempeh (Hesseltine and Wang 1972).
Poisonings from tempeh bongkrek (made with coconut rather than the usual soybeans) continued to be a problem. From 1951 (when detailed records first began to be kept) until 1976, some 7,216 cases of bongkrek poisoning were reported in Central Java and 86 of these people (1.2%) died. In 1958 Harsono showed that the use of the acidic leaves of an Oxalis species (which grows everywhere as a weed in Banyumas) could be used to prevent toxicity in bongkrek. Unfortunately, this simple safety measure has not been adopted (van Veen 1967). In 1960 van Damme et al. elucidated the structure of toxoflavin. Laws have been passed to try to prevent production of tempeh bongkrek by unlicensed amateurs, but these too have not worked. So the periodic poisonings have continued into the 1980s. Fortunately soybeans are not involved.
On 11 March 1979 a key event took place in Indonesia with the organization of KOPTI, the Cooperative of Tempeh and Tofu Producers of Indonesia, with Achmad Rouzni Noor as director in Jakarta. Noor had a deep personal interest in helping tempeh makers to grow, modernize, and thrive. And national laws passed in 1979?? governing import and distribution of soybeans virtually compelled most tempeh makers to join KOPTI. By 1983 KOPTI had over 28,000 members in Java; 72% of these ran home industries. KOPTI's main functions were: (1) to buy basic materials (soybeans, inoculum, oil, etc.) collectively for its members at lower prices, (2) to improve member's production by developing new processing equipment (such as dehulling machines), helping members improve the quantity and quality of their products through better sanitation and preservation practices, and developing new products, (3) to provide marketing services, (4) and to serve as a source of capital for loans and helping members to form cooperatives. In part because of KOPTI, tempeh production was on the upswing in Indonesia by the early 1980s and the industry was modernizing. In 1984 Ko Swan Djien was able to write: "From my recent visit to Indonesia I get the satisfactory feeling that our efforts to have fermented foods valued in their right proportion are not in vain. Tempe is no longer considered an inferior food. Nowadays Indonesians are as proud of THEIR tempe as Japanese are of their sake, and French of their wine...!" (personal communication).
Shurtleff and Aoyagi (1979) conducted an informal survey in Java to identify which were Indonesia's best known and best liked tempeh recipes. The number preceding each recipe name indicates the order of "best known," with (1) being the best known. The number after the English recipe name indicates the quality ranking with (1) being the best liked. 1. Tempeh Goreng (Deep-Fried Tempeh with Seasonings; 2) 2. Tempeh Bachem (Tempeh Cutlets; 4), 3. Keripik Tempeh (Tempeh Chips; 6), 4. Sayur Lodeh (Tempeh & Vegetables in Coconut Milk Soup; 7), 5. Sambal Goreng Tempeh (Spicy-Fried Tempeh in Coconut Milk; 3), 6. Terik Tempeh (Tempeh in Coconut Milk Sauce; 5), 7. Sambal Goreng Tempeh Kering (Crunchy Chili-Fried Tempeh Topping, 1). Surprisingly the least well known of the "Top Seven" was the best liked.
Java is still the Mecca of the tempeh world, yet over the centuries, wherever Javanese settlers have gone, they have taken tempeh with them. Today it is widely produced and consumed in Surinam (where 30% of the population is Indonesian), and on the west and south coasts of Peninsular Malaysia. To a lesser extent it is consumed in Singapore, New Caledonia, and the other Indonesian Islands (especially Sumatra). Tempeh is also increasingly popular in the Netherlands, where it was introduced by immigrants from Indonesia in the 1940s.
HISTORY OF TEMPEH IN EUROPE AND AUSTRALASIA
History of Tempeh in Europe . As noted previously, all of the references to and articles about tempeh written between 1875 and the early 1950s were written by Europeans, most of them Dutchmen. Senior authors of references prior to 1940 included Gericke and Roorda (1875, 1901), Prinsen Geerligs (1895, 1896), Boorsma (1900), Vorderman (1902), Heyne (1913), Jansen (1923, 1924), Ochse (1931), van Veen (1932, 1933, 1934, 1935, 1936, 1938), Mertens (1933), Amar and Grevenstuk (1935), and Burkill (1935). Yet, perhaps because Dutch was not a widely read or spoken language and tempeh was not known in countries more famous for soyfoods such as Japan and China, tempeh was rarely mentioned in the numerous articles about soyfoods published in French, German, and English prior to the 1950s. Nor are there any records of tempeh being made in Europe during this time. The only two European works in English that mentioned tempeh during this period were those by Ochse (1931) and Burkill (1935), and both were encyclopedic works about the foods and plants of Malaysia and Indonesia; Ochse's work was originally published in Dutch.
Relatively little was published about tempeh in Europe between 1940 and 1959, and most articles focused on its role in prisoner of war camps in Southeast Asia. There were articles by van Veen (1946, in Dutch), Roelofsen (1946, in Dutch), de Bruyn et al. (1947, in Dutch), Tammes (1950, in Dutch), van Veen and Schaefer (1950), Smith and Woodruff (1951), Grant (1951), Dupont (1954), and Autret and van Veen (1955); the latter five articles were all in English. Most of these have been discussed earlier at Indonesia. Boedijn (1958) reported that Rhizopus oligosporus can always be isolated from tempeh, implying that it is the primary organism in tempeh.
All of the first tempeh companies in Europe were started in the Netherlands by immigrants from Indonesia. The earliest of these, called ENTI, was founded in April 1946 by a Dutch couple whose last name was Wedding. While living in Indonesia, they had learned to make tempeh. Bringing their starter culture and recipe to the Netherlands, they began to make Europe's earliest known tempeh there on a home scale for friends and relatives. Gradually ENTI grew and became a commercial operation. By the early 1970s they were making 2,000 lb of tempeh a day. In about 1974 they sold the company (located in Zevenhuizen) to Mrs. L.J. Duson, who ran it until January 1984, when she closed it.
Firma E.S. Lembekker, founded in January 1959, was Europe's second tempeh company, and it may have been the first to sell tempeh commercially. In January 1984 it became Europe's oldest existing tempeh company.
Interest in tempeh in Europe began to increase starting in the 1960s. Articles were published by Roelofsen and Thalens (1964; changes in B vitamins), Stanton and Wallbridge (1969; a tempeh-like product made from cassava but with improved nutritional value), Thio (1972, 1975; small scale production and recipes), Jensen and Djurtoft (1976; a large report from Denmark on legume and cereal grain tempehs), Djurtoft and Jensen (1977, tempeh from various African grains and beans), Andersson (1977, volatile components and yellow pea tempeh, from Sweden), and Bahi El-Din et al. (1977; Sudanese researchers at Wageningen, Netherlands). Among these researchers, Thio Goan Loo from Indonesia was especially active in teaching people in Third World countries about tempeh. In 1972 he wrote about tempeh for use in Zambia (Africa) and spent three months in 1979 teaching tempeh production and recipes in Sri Lanka.
Europe's earliest known popular article on tempeh was an excellent 7-page feature story with nine photographs published in 1982 in Le Compas in French. In 1982 Soja Total , a translation of The Farm Vegetarian Cookbook (Hagler 1978), containing 13 pages of information on tempeh, was published in Germany. In 1985 Das Tempeh Buch , an updated and expanded translation of The Book of Tempeh (Shurtleff and Aoyagi 1979), was also published in Germany. Thus by 1984 there was more information on tempeh available in German than in any other continental European language, including Dutch. However the absence of a center of focused research efforts and a good source of low-cost tempeh cultures, such as the centers at Geneva and Peoria in the US, restricted the development of widespread popular interest in tempeh in Europe. Fortunately in 1984 the Centraalbureau voor Schimmelcultures in Baarn, Netherlands, began to promote their tempeh cultures quite actively.
Europe's largest tempeh company, Tempé Produkten B.V. (Tempe Products Inc., named Handelsonderneming van Dappern until April 1983) was founded in 1969 by Robert van Dappern, with the help of his Dutch father (Herman), his Indonesian mother (Aveline), and his Dutch-Indonesian wife. He paid a Dutch-Indonesian man named Mr. Remmert a substantial sum of money to teach him how to make tempeh. By 1970 they were making tempeh in a small warehouse in Rotterdam. Initially they sold all of their tempeh to a couple of Holland's many Indonesian stores, but then they hired his wife's father, a well-known Indonesian, to deliver to the wider Indonesian community. The company began to grow, but all of the tempeh was being consumed by Indonesians living in the Netherlands. In January 1972 they moved the thriving company to Kerkrade, in southern Holland near the family home in Heerlen, rented a bigger building, and started mass production. Ed van Dappern, the second brother, joined the company as an equal partner. In 1979 Robert sent his wife's brother, Ike van Gessel, to Los Angeles to set up a tempeh plant there. Ike rented a building but, because of the European recession during the early 1980s and the need for capital to expand the business in the Netherlands, he had to cancel the lease and call off the project, at a substantial financial loss. In June 1980 the company bought a $1,000,000 modern factory in Kerkrade and expanded again. By mid-1982 Tempé Produkten was producing 6,000 to 8,000 pounds of tempeh a week, making it the largest tempeh company in the world. By early 1984 production had increased to 13,200 pounds (6,000 kg) a week, and an estimated 10% of this was consumed by non-Indonesians. By Dec. 1992 the company was producing 11,000 pounds (5,000 kg) of tempeh a week.
The family developed their own proprietary method for making tempeh starter culture. They developed a leaflet on tempeh, gave demonstrations on making and cooking with tempeh, and got tempeh to be sold at the Central Market, with the result that more and more of the greengrocers, who buy their vegetables there early each morning, started selling tempeh (and tofu). The company exported tempeh and tempeh products to England, Germany, Belgium, and Luxembourg via a major distributor. Robert's Indonesian mother, Aveline, was in charge of preparing these (van Gessel 1982; Welters 1982; van Dappern 1984, each personal communications). By 1984 Tempé Produkten was the world's second largest tempeh manufacturer, after Marusan-Ai in Japan.
In June 1985, Tempé Producten added a new soyfood product to its line - tofu, and by 1991 the company was the largest tofu producer in The Netherlands.
Prior to early 1981 all of Europe's tempeh companies were located in the Netherlands and run by older Dutchmen catering largely to an Indonesian clientele. Europe's first generation of "New Age" tempeh shops was started from 1981 by young people interested in natural foods and/or macrobiotics. Europe's earliest known New Age tempeh company was Paul's Tofu & Tempeh, which was in operation by January 1981 at 155 Archway Rd., Highgate, in London. JAKSO, the first New Age shop in the Netherlands, started in July 1981. By January 1982 there were 7 tempeh shops operating in Europe; by January 1984 there were 18. Of these, 7 were in the Netherlands, 3 in Austria, 2 each in England and West Germany, and 1 each in Belgium, France, Italy, and Sweden. Total tempeh production in the Netherlands was about 4,500 kg a week (10,000 cakes of 1 pound each) in 1982, rising to 12,000 kg a week in 1984.
By 1980 another center of interest in tempeh had developed at the Department of Botany and Microbiology, University College of Wales, Aberystwyth, Wales, UK. There Dr. J. Hedger and Mr. T. Basuki (from Indonesia) were planning?? to start a tempeh factory, had produced a 4-page leaflet on "Tempe--An Indonesian Fermented Soybean Food," and had written a script for a BBC program "Tomorrow's World," on tempeh, which was broadcast in the summer of 1979. At that time tempeh was also occasionally sold in London, but the name of the manufacturer was not given (O'Neill 1980). In 1982 Hedger wrote a brief article on tempeh production.
History of Tempeh in Australia . Australian interest in tempeh began in about 1977, when McComb published an excellent BS thesis on the use of sweet narrow-leafed lupins to make tempeh. It contained one of the best summaries of the literature to date, plus much original research. A summary of this work was given by Kidby et al. (1977). The earliest known Australian tempeh companies were started in about 1980, and by March 1981 there were three small ones, all run by young "New Age" people, interested in natural foods, meatless diets, and alternative lifestyles. The first two to start were Dharma, part of Earth Foods in Waverley, run by Swami Veetdharma, and a small shop at Bodhi Farm in Channon, New South Wales, run by John Seed. Cyril and Elly Cain founded Beancoast Soyfoods in Eumundi, Queensland, and started making tempeh in July 1982. In March 1982 Ziruiz magazine published a long popular article "Terrific Tempeh" by Shurtleff and Aoyagi. By early 1983 Earth Angel was making okara tempeh. By 1984 there were five tempeh companies in Australia, all quite small.
Because of Australia's proximity to Indonesia, both countries could learn much from each other about traditional and modern tempeh making.
HISTORY OF TEMPEH IN THE UNITED STATES AND CANADA
Early Years in America (1954-1969) . Interest in tempeh in the United States began at a surprisingly late date. As noted previously, early English-language articles on tempeh had been written by Ochse (1931) and Burkill (1935), both published outside the US. The earliest known reference to tempeh in a US publication appeared in 1946, when an article by Gerold Stahel, writing from Surinam in South America about tempeh in Surinam and in New Guinea, was published in the Journal of the New York Botanical Garden . A summary appeared in November of that year in Soybean Digest . These articles appeared just 50 years after the first reference to tempeh was published in Europe by Prinsen Geerligs. In 1955 Autret and van Veen (both working for the Nutrition Division of the Food and Agriculture Organization of the United Nations, outside the USA) published "Possible Sources of Proteins for Child Feeding in Underdeveloped Countries" in the American Journal of Clinical Nutrition . They were the first suggest tempeh as a protein-rich, nutritious, and low-cost food for infants and children in Third World countries. They mentioned tempeh only briefly and noted that soymilk would probably be better suited for feeding children.
Research on tempeh in the US was started in 1954 by Dr. Paul György, a pediatrician and researcher at the Philadelphia General Hospital, and Professor of Pediatrics at the University of Pennsylvania. György had been to Indonesia many times, knew tempeh well, and (like Autret and van Veen) thought that it offered a way of improving the diets of infants and children in Third World countries. György received his first tempeh from Indonesia and Southern Rhodesian in 1954 and 1955. Ms. Kiku Murata of Japan worked with Gyorgy in the US investigating tempeh during 1959 and 1960. Following largely futile attempts to make tempeh in his own laboratory and lacking adequate facilities for making larger quantities of fermented foods, György worked out a cooperative arrangement in 1959 to have the tempeh made under the supervision of Dr. Hand and Dr. Steinkraus at New York State Agricultural Experiment Station, Cornell University, Geneva, New York. The first publication from this work did not appear until 1961, when György wrote "The Nutritive Value of Tempeh." György gradually moved his research away from a focus on child feeding programs toward the more narrow study of antioxidants in tempeh, which might prevent rancidification of tempeh or other foods.
As noted earlier at Indonesia, a great expansion of interest in tempeh began in the early 1960s, largely because of the pioneering, in-depth research at two centers: Cornell University's New York State Agricultural Experiment Station at Geneva, New York, under the leadership of Dr. Keith H. Steinkraus; and the USDA Northern Regional Research Center at Peoria, Illinois, under the leadership of Dr. Clifford W. Hesseltine. Each center became actively interested in tempeh because of the arrival of an Indonesian researcher. Whereas approximately 15 scientific on tempeh had been published worldwide before 1960, more than 60 were published from 1960 to 1979. Important, original investigations were done on pure culture fermentations, microbiological and biochemical changes during tempeh fermentation, tempeh's nutritional value, and industrial production of tempeh. This research awakened a new interest in tempeh among microbiologists and food scientists worldwide. Moreover, with this research, the world center of interest in and research on tempeh shifted from Indonesia and the Netherlands to the USA.
In the summer of 1958, when Miss YAP Bwee Hwa from Indonesia started her research on tempeh in New York. Active in nutritional circles in Indonesia, she was the first Indonesian to study tempeh in America; she brought her own little bottle of dried tempeh inoculum with her. She did her course work and rat feeding experiments under the direction of Prof. Louise Daniel and Dr. Richard Barnes in the Graduate School of Nutrition at Cornell University, while pursuing her investigations of tempeh production under Dr. Steinkraus in the allied Department of Food Science and Technology at the New York State Agricultural Experiment Station. Dr. Hand, then head of the latter Department, was very active in nutritional circles and knew of the United Nations' interest in tempeh. In early 1959 Steinkraus, while on a trip to check the UNICEF-supported Saridele soymilk plant in Indonesia, visited a number of tempeh shops, thus becoming the first American ever to study tempeh in its homeland. Also in 1959 Steinkraus' Cornell University group began making tempeh for Dr. György in Pennsylvania.
The first article on tempeh by Americans was written in 1960 when Steinkraus, Yap, van Buren, Provvidenti, and Hand published their now classic "Studies on Tempeh--An Indonesian Fermented Food." This paper (submitted for publication in September 1959) incorporated Miss Yap's tempeh research, plus additional investigations by Steinkraus' group on essential microorganisms, mycelial penetration of the soybeans, etc. In 1961 this paper appeared in a publication by the National Research Council of the National Academy of Sciences. In June 1960 Miss Yap, as part of her graduate degree in nutrition, submitted her MS thesis titled "Nutritional and Chemical Studies on Tempeh, an Indonesian Soybean Product." Innovations in tempeh production described in these papers included use of lactic acid instead of a prefermentation to acidify the soybean soak water, incubation of the tempeh in stainless steel trays, dehulling the soybeans mechanically (with an electric vegetable peeler), growing the starter spores on bran, and dehydration of the tempeh in a circulating hot air oven. Yap found the PER of tempeh to be 2.5, midway between soybeans (2.3) and casein (2.7). Rats ate 1.5 times as much tempeh as cooked soybeans, and grew almost as fast as those fed casein. Changes in temperature, soluble solids, and soluble nitrogen, and pH during tempeh fermentation were measured and plotted. Yap left the US in April 1962 for Germany, where she worked as a researcher, first for a wine institute, then after 1970 for a chemical-pharmaceutical company.
During the 1960s the Cornell University Group, consisting of interdisciplinary scientists from both the Agricultural Experiment Station and Cornell University, worked together to publish at least 13 original scientific articles on all aspects of tempeh. The group included Steinkraus, Yap, van Buren, Wagenknecht, Provvidenti, Hand, Hackler, Stillings, van Veen, and Shallenberger. Steinkraus was the senior author of 6 papers during this period. Particularly important for the coming new generation of US tempeh manufacturers were his "Pilot Plant Studies on Tempeh" (1962), "Research on Tempeh Technology in the United States" (1964), and "A Pilot Plant Process for the Production of Dehydrated Tempeh" (1965), in which all of the necessary equipment and its manufacturers was described. These represented the first attempts to develop a process for making tempeh in an industrialized country with a temperate climate. Changes during the tempeh fermentation were studied in detail, including changes in lipids (Wagenknecht et al. 1961), in amino acids (Stillings and Hackler 1965), and in carbohydrates (Shallenberger 1967). Hackler et al. (1964) studied utilization of tempeh protein by rats. Van Veen, who had done pioneering research on tempeh in Indonesia as early as 1932 and had arrived at Cornell in 1962 as a professor of International Nutrition, was senior author of seven papers related to tempeh between 1962 and 1970, including an original 1968 study on peanut tempeh.
In 1960 a second US tempeh research program was started under the direction of Dr. Clifford W. Hesseltine at the USDA Northern Regional Research Center (NRRC) at Peoria, Illinois. As early as May 1948 the NRRC had been sent a tempeh culture ( Rhizopus nigricans ) from Central Sugar Society (N.V. Centrale Suiker Maatschappij) in Amsterdam, together with instructions for making tempeh, but apparently nothing was done with it. Hesseltine first learned of tempeh from papers by Stahel (1946) and van Veen and Schaefer (1950). Much of the interest in tempeh starting in 1960 developed because KO Swan Djien of the Bandung Institute of Technology's Laboratory of Microbiology arrived at the NRRC that year to study industrial fermentations. Hesseltine suggested that he study tempeh; Ko showed Hesseltine and his group how to prepare it. The first publications appeared in 1961 with Ko and Hesseltine's "Indonesian Fermented Foods" and 1962 with Hesseltine's "Research at Northern Regional Research Laboratory on Fermented Foods." From the early 1960s on an interdisciplinary team of researchers at Peoria began to study many facets of tempeh and to develop new types of tempeh and processing techniques. Key figures in this team, in addition to Hesseltine and Ko were H.L. Wang, A.K. Smith, A.F. Martinelli, Mable Smith, W.G. Sorenson, and E.W. Swain. During the 1960s they published 17 original scientific papers (including two public service patents) about tempeh, plus four derivative articles; Hesseltine was senior author of 12 of these, Wang of four, Ko and A.K. Smith of two each, and Martinelli and Sorenson of one each.
In 1963 Hesseltine and co-workers published their first major tempeh study "Investigations of Tempeh, an Indonesian Food." That same year they discovered a mold inhibitor in soybeans. In 1963 and 1964 A.K. Smith and co-workers published pioneering studies on the nutritive value of tempeh in relation to various processing techniques. In 1964 Dr. Martinelli (a Brazilian scientist studying tempeh at the NRRC) and Hesseltine developed a new method for incubating tempeh in perforated plastic bags. It soon became widely used by commercial tempeh producers in both Indonesia and North America, a nice example of cultural cross-fertilization. In the same paper they described fermentation of tempeh in metal and wooden trays, the dry dehulling of soybeans, and the preparation of tempeh from full-fat soy grits. In 1965 Hesseltine wrote a review and history of research on tempeh microbiology and biochemistry. In 1966 and 1967 Hesseltine and Wang published the world's first studies showing that delicious tempeh containing higher quality protein could be prepared using soy-and-grain mixtures (including wheat and rice) or cereal grains alone. In 1969 Wang and co-workers discovered that Rhizopus oligosporus in tempeh produces an antibacterial compound or antibiotic, which is very active against a number of Gram-positive bacteria, including Staphylococcus aureus and Bacillus subtilis , and which retains its activity even after cooking. This supports the view of natives and of some scientists that those who eat tempeh daily have fewer intestinal infections. Hesseltine and Wang sent samples of their tempeh to Dr. Doris Calloway at the University of California, Berkeley. She found in 1971 that tempeh, unlike most foods made from beans, does not cause flatulence. David and Verma (1981) suggested that the antibacterial substance in tempeh may be the cause of this lack of flatulence; it might inhibit the growth of gram-positive Clostridium bacteria, which are known to produce gas in the intestines. News of the NRRC discoveries on tempeh was disseminated by Soybean Digest (1965, 1967) and the USDA's Agricultural Research (1966, 1969).
A key component of the tempeh research at the NRRC concerned identification of the main microorganisms in the fermentation. It has never been clear what the original source of these molds in Indonesia was. Smith and Woodruff (1951) reported that prisoners in Japanese camps in Indonesia during World War II obtained their original tempeh mold culture from the withered petals of the hibiscus plant. Others have said that they came from banana leaves. The genus Rhizopus was discovered and named in 1820 by Ehrenberg. In 1895 Went and Prinsen Geerligs first described the species Rhizopus oryzae , which was investigated in detail by Wehmer in 1900 and 1901. Until the mid-1960s many microbiologists worldwide (Vorderman 1902; Stahel 1946; van Veen and Schaefer 1950; Dupont 1954; Steinkraus et al. 1960) thought R. oryzae was the primary microorganism responsible for the tempeh fermentation. In 1936 Lockwood and co-workers had studied the physiology of R. oryzae at the NRRC. In 1905 the Japanese mycologist Kendo Saito first described Rhizopus oligosporus on rice meal cakes which came from Shantung province in China, where they were used in making a rice-based fermented alcoholic beverage. Saito did not mention tempeh. In 1958 Boedijn reported that R. oligosporus could always be isolated from tempeh, implying that it was the primary fermentation organism. In 1962, after observing 50 tempeh strains from various tempeh sources, Hesseltine identified R. oligosporus as the chief tempeh mold. Ko (1965) reported collecting 81 samples of tempeh from various places in Java and Sumatra. Isolation of 116 pure cultures revealed that R. oligosporus was always present in good quality tempeh, thereby establishing without a doubt that it was the typical dominant species used. Indonesian researchers, however, maintain that the best quality tempeh contains a mixed culture. By the late 1970s the most widely used tempeh culture in the Western world was R. oligosporus strain NRRL 2710. This strain, brought to the US from Indonesia by MS. Yap in 1957, isolated by Steinkraus' group, and first identified in Hesseltine's lab, continued to be widely distributed from the NRRC culture collection.
It is not known for sure when the first commercial tempeh was made in the US. After the long and bloody war that drove the Dutch out of Indonesia and led to Indonesian independence in 1949, tens of thousands of Dutch and Dutch-Indonesian families were uprooted. Most tried to go to Holland, but the country was too small and the native Indonesians found it too cold. The United States set a quota in 1950 allowing 25,000 of these refugees to immigrate. Only about 10% were culturally native Indonesian; the rest were "Indos," i.e. Dutch-Indonesians or Chinese-Indonesians. Most went to warm areas such as California and Florida. In 1950 an estimated 500 of these settlers arrived in California. The first of these known to have started a tempeh shop was Mary Otten, who in 1961 began making tempeh in her basement on Stannage Avenue in Albany, California. She sold it to her friends and served it at parties that she catered. For starter culture she used ragi (an Indonesian starter that comes in small cakes) flown in from Java, until she learned how to make her own in 1973. In 1967 she started Java Restaurant and served many tempeh dishes. Then in 1974 she and her daughter, Irene, started Otten's Indonesian Foods, which by 1981 was making tempeh plus a full line of Indonesian tempeh-based foods under the brand name Joy of Java. These foods included Sweet & Sour Tempeh and Sayur Lodeh Tempeh.
The second earliest known tempeh shop in California (and in the USA) was Runnels Foods, which opened in Los Angeles, California in 1962. Also in Los Angeles, Toko Baru started in 1969 and Bali Foods started in 1975. Thus America's first generation of tempeh shops were all located in California and all run by Indonesian-Americans.