History of Tofu - Page 7

by William Shurtleff and Akiko Aoyagi

A Chapter from the Unpublished Manuscript, History of Soybeans and
Soyfoods, 1100 B.C. to the 1980s

HISTORY OF FROZEN AND DRIED-FROZEN TOFU

Frozen Tofu. Frozen tofu is said to have been developed in China where it is called dong doufu or bing doufu. It was made by setting cakes of firm tofu out in the snow. The earliest known mention is from the Ch'ing dynasty (1662-1912; Shinoda 1974).

The history of frozen and dried frozen tofu in Japan is one of the best documented for any soyfood other than shoyu, thanks to a landmark 571-page tome, History of Dried-Frozen Tofu by Akira Miyashita (1962); it is richly documented, and contains many photographs. This, plus an excellent historical essay on Kori-dofu by Kudo (1976) and the detailed Thirty year History of Asahimatsu (Asahimatsu Shokuhin 1981; Japan's largest manufacturer) provide abundant, reliable information on this subject.

In Japan, frozen tofu was developed before dried-frozen tofu. It had two centers of origin: (1) Mt. Koya and the Kyoto-Osaka area (Kansai) and (2) Shinshu and the northeast provinces. In the Mt. Koya area it was typically called ichiya-gori (literally "one-night frozen") but also hayako-gori ("quick becomes frozen") and, from the Edo period, nama-gori ("fresh frozen"). On 2600-foot Mt. Koya, where Kobo Daishi founded a great monastery and the headquarters of the Shingon sect in 816 A.D., frozen tofu is thought to have originated at an early date, probably in the early 1200s. According to the most popular legend, during the winter a young monk accidentally left a cake of tofu outdoors (some say it was offered at an outdoor altar). The next day, when they thawed the frozen tofu, the monks found it had a unique texture like a delicate sponge, and a nice flavor. A second legend states that frozen tofu on Mt. Koya started with a Shingon priest named Kakkai-sonja (1140-1223). He was said to be a great priest with both wisdom and magical powers, including the power of flight. It is said that one night he flew back from Kyoto with provisions, placed an offering of tofu on the outdoor altar, and found it frozen the next morning (Miyashita 1962). Miyashita, Japan's foremost expert on frozen tofu history, believes that frozen tofu began to be made among the farmers by the mid-1500s and became popular during the next 50 years. In 1629 the Ryori Monogatari made the first mention of putting tofu out in the show to let it freeze. By the late 1600s and 1700s many farmers in southwestern Japan (Kinki and Chugoku areas) would buy tofu during the winter, slice it thinly, place it on a board or shallow bamboo colander, and leave it out to freeze on very cold nights. This process was described in the Honcho Shokkan of 1690 and in more detail in the Tofu Hyakuchin of 1782 (Miyashita 1962).

The second center of frozen tofu was in northern Japan in Shinshu, Tohoku, and Hokkaido. There frozen tofu was called shimi-dofu.

Dried-Frozen Tofu in Japan. One of the world's earliest meat analogs and lightweight staple soyfoods, dried-frozen tofu originated in Japan, where there was a long history of freezing foods containing a large amount of water, then thawing and drying them as a way of removing most of the water at little cost to produce a lightweight dehydrated food that would store well. Agar, radishes, buckwheat noodles, konnyaku, and mochi (cakes of pounded glutinous rice) were all processed in this way. By the 1980s only dried frozen tofu and agar remained as commercial products. There are no foods processed like this in the West.

In Japan the industry making dried-frozen tofu has long been considered as a separate one from the industry making other types of tofu. It has its own trade association and government statistics are kept separately. Hence the separate section in this chapter.

Dried-frozen tofu, made by thawing and then drying frozen tofu, originated after frozen tofu in the same two centers. That which originated on Mt. Koya came to be called Koya-dofu. According to undocumented legend, it was developed by a Shingon priest named Mokujiki Shonin, who succeeded Kakkai-sonja. He obtained large amounts of soybeans from the head Shingon temple and encouraged each of the mountain temples to make their own tofu, miso, and shoyu. In order to preserve some of the frozen tofu until the spring equinox, he developed a system for drying it as follows. Firm tofu was frozen outdoors in the snow on cold windy nights, allowed to stand on shelves in a shed for 5-15 days at temperatures below freezing, thawed in warm water and pressed lightly to expel the melted ice, then dried in the shed using heat from charcoal braziers. Mokujiki Shonin died in about 1609. Yet the Ryori Monogatari ("tale of food") in 1629 mentioned dried-frozen tofu (what term??), as did the Teitoku Bunsho of 1650, stating that dried-frozen tofu was used as a gift from Mt. Koya. The popularity of the new food spread when farming villages in the area around Mt. Koya learned the freezing and drying techniques from the monks, and soon many large freezing and drying sheds were built in the surrounding mountain valleys. "Koya-dofu" soon came to be made on a fairly large scale as a communal wintertime occupation and source of income during the lean months. In 1710 the Wakan Sansai Zukai mentioned that Koya-dofu was a famous product of the area (Kii-no-kuni). During the next 2 centuries its popularity spread widely, especially after 1700 as it became an important ingredient in Buddhist Vegetarian Cookery (shojin ryori). The increased popularity led to improvements in the processing method. In 1911 Koya-dofu started to be made on an even larger scale throughout the year using artificial refrigeration (Miyashita 1962).

The second traditional center of experimentation with dried-frozen tofu was in the cold mountains of Nagano, far to the northeast of Tokyo, where the product was first made during the mid-1500s. No one is certain who first developed this method but it is said that the famous feudal lord and warrior, Takeda Shingen (1521-1573), thought of drying frozen tofu to make a lightweight, nutritious food that his soldiers could carry in their backpacks. There, in Nagano, a new drying process was developed. Firm tofu, after being frozen solid on boards in the snow, was wrapped in straw mats and placed in a cold barn for 1-7 days. Then five pieces of tofu at a time were tied together with several pieces of rice straw and these strands were hung from poles under the eaves of farmhouses (where they received no sunlight). After several weeks of thawing and drying during the day then freezing at night, the tofu became as hard and dry as a dry sponge. This new technique eliminated the special shed and drying equipment used on Mount Koya. Soon farmers in Nagano were making this tofu, carrying the lightweight product from village to village in backpacks, and selling it as a source of wintertime income. The new product, first called shimi-dofu, later?? came to be known as kori-dofu ("frozen tofu"). To this day, here and there in the Nagano area, strands of drying frozen tofu can be seen hanging under the verandas of farmhouses and the eves of temples.

By the mid-1700s the production of dried-frozen tofu in Nagano started to become a commercial industry. This part of the Japanese Alps was (and still is) ideally suited for making this product due to its cold weather, its abundant and inexpensive pure well water, its low wage structure, and, in recent times, its many dairy farms whose cows consume the leftover okara. Since the finished tofu was neither perishable nor fragile, it was well suited to large-scale, centralized production and nationwide (eventually worldwide) distribution. In 1900?? artificial refrigeration was first used (Where?? Source??) in making dried-frozen tofu; this laid the foundation for year-round, factory production. Gradually the product spread throughout Japan; in most places it was called kori-dofu, except in the Kansai district (the area around Kyoto and Mt. Koya), where it kept the name Koya-dofu. During the Russo-Japanese War (1904-05) dried-frozen tofu was used in the Japanese army rations (Senft 1906).

In 1913 the more advanced drying method used around Mt. Koya was imported to Nagano prefecture, where manufacturers made a great effort to improve their techniques and expand the scale of their production and their markets. Consumers in the Kyoto-Osaka area at that time wanted a soft frozen tofu, so techniques for making such a product were developed. In 1925 starch was added at the stage of making fresh tofu to get a softer texture. Then in 1928 it was found that if, after freezing, the thawed tofu was steeped in a solution of baking soda (sodium bicarbonate), it swelled during cooking and became softer and more absorbent than the traditional product. Similar "expanding-and-softening" agents (bonanzai) have been used ever since in commercial (but not in farmhouse and homemade) dried-frozen tofu. In 1929 a dramatic event occurred, which changed the course of dried-frozen tofu history. Manufacturers in Nagano discovered (accidentally, when trying to remove the sour baking-soda taste) that if the dried tofu was put in a chamber filled with ammonia just before packing and sealing, it got very soft and expanded nicely upon cooking. Thereafter the dried-frozen tofu from Nagano became very popular in the distant Kyoto-Osaka area. The ammonia gas technique continued to be used until 1971. Then in 1972 baking soda again came to be used in a new, improved form (potassium carbonate, potassium phosphate, or sodium carbonate or phosphate), which now contained various quantities of various salts and was known in Japan as kansui. Not only was the new tofu free of the unpleasant ammonia smell, it had better stability (the ammonia oxidized some of the tofu's oils) and a longer shelf life (up to 8 months at average temperatures and 12 months if kept cold). And its quality was less affected by temperature changes during storage. The resulting product expanded nicely, became very soft after cooking, and had an excellent flavor. As of 1981, all major producers used kansui as the expanding-and-softening agent for most of their dried-frozen tofu, however some tofu was still prepared with ammonia since the process was said to be simpler and there was less loss of solids.

Starting in the early 1960s, the large producers of dried-frozen tofu started to get much larger and many of the smaller, more traditional producers began to disappear. At the same time the larger producers began to use large amounts of soybeans (Harosoy and Hawkeye varieties) imported from America. In 1960 the largest and most modern dried-frozen tofu factory of its time was built on the outskirts of Nagano city; it used 12 tons?? of US soybeans a day (Hayashi 1960). By 1969 the dried-frozen tofu industry consumed 30,000 tonnes a year of soybeans, about 10% of that used for regular tofu, and the rate of use of the former was increasing at the rate of about 10% a year. There were about 40 producers in the industry and each used an average of 2-2.5 tonnes of dry soybeans a day. The 5-6 largest factories, which together consumed over 10 tonnes of dry soybeans a day, had over 80% of the total market. On a protein basis, the product sold for less than fresh tofu since, even though more processing was required, the factories were large and mechanized. Yet the basic production principles were the same as those used in ancient times.

As of 1980, some 90% of the production of dried-frozen tofu in Japan has come to be concentrated in four huge companies, each in the Nagano Area. Asahimatsu (including Daiya) is the largest company. Founded in 1950, it accounted for over 55% of Japan's dried-frozen tofu production, ran three large factories, employed over 300 people, and used 41 tonnes of dry soybeans daily to turn out 1,200,000 cakes of tofu. Other large makers were Misuzu-dofu, Nagai Sogo Shokuhin, Yamaguchi-ya, Taishi Shokuhin Kogyo, and Habutae-dofu. Japan's 28 producers of dried-frozen tofu used about 50,000 tonnes of dry soybeans each year, which was about 10% of the total used for all types of tofu. The center of consumption dried-frozen tofu was the far-away Kyoto-Osaka-Nara area (Kansai), which accounted for about 43% of all dried-frozen tofu use.

Dried-frozen tofu was also sold in four other forms, which originated in the Nagano area. Traditional dried-frozen tofu was made from tofu containing no expanding agent, tied into strands with rice straw, and sold mostly as a tourist item or in natural food stores. Tofu meal and tofu flour were made by grinding the dried tofu. And tofu croutons were made by cutting dried-frozen tofu into l/2-inch cubes.

Dried-Frozen Tofu in the West. The earliest known mention of dried-frozen tofu in the West was by Paillieux in 1880: "Sometimes during the winter tofu is frozen, then dried to give it a sponge-like texture. In this state it lasts a long time and can be cooked in various ways." Kinch (1882) of England gave a nutritional analysis of dried-frozen tofu, which was summarized by Schulze (1891?? ref??). Inouye (1895) also gave a nutritional analysis of "kori-dofu" and a brief description of how it was produced. The first mention in the US was by Trimble in 1896. It was also mentioned by Rein (1899; he called it kori-tofu). Hosie (1901) first mentioned Chinese frozen tofu (he called it tung tou-fu). Loew (1904) described how "kori-tofu" was made in an article on "The Use of Frost in Making Japanese Foods." Senft (1906), of the German Military Food Administration, discussed dried-frozen tofu in the context of preserved foods used by the Japanese military. He mentioned its use during the Russo-Japanese War and suggested its possible use by the German military. Horvath (1927) stated that it contained 58% protein. The first details in English on the manufacture of "kori tofu" were given by Watanabe in 1969 and 1974.

The most extensive information to date on all aspects of the product (history, nutrition, production, recipes) was given in The Book of Tofu by Shurtleff and Aoyagi (1975). They introduced the term "dried-frozen tofu," rejecting the more fashionable but inaccurate term "freeze-dried tofu." Their 27 recipes, both Japanese and Western, were the first published in the West. In Tofu & Soymilk Production (1979) they gave details on the manufacturing process and many illustrations. In 1979 Bauer and Andersen, in The Tofu Cookbook, introduced homemade frozen tofu as PSP (Processed Soy Protein), suggesting that it be used as a substitute or extender for ground beef or TSP (Textured Soy Protein, almost always made from defatted soy meal). The book gave more than ten creative recipes. The advantages of crumbled frozen tofu over TVP are that it does not cause flatulence (as TVP definitely does) and it is a more natural product.

By the mid-1970s at least two brands of imported Japanese dried-frozen tofu were being sold in America, almost entirely at Japanese food stores. In late 1981 Marusan Inc. introduced "Kori-Tofu" which they marketed mostly to the natural foods trade, advertising it quite extensively as part of a line of imported Japanese natural foods. We feel that there is a large potential market for dried-frozen tofu in America, for use as an ingredient in lightweight camping and backpacking meals, as well as in freeze-dried or instant soups, and natural foods or vegetarian cuisine. Its tender meaty texture and ability to absorb other flavors readily make it most appealing.

BRIEF HISTORIES OF OTHER SPECIAL TYPES OF TOFU

We are including this section to give a greater sense of continuity and detail in the histories of the various special types of tofu.

Firm Tofu. Most of the tofu made in China has always been firm tofu; it has a longer storage life, especially in warm climates, can be transported more easily without breaking, has a higher nutrient density, a richer flavor, and holds together better during stir frying, deep-frying, or slicing. Much of the tofu in Southeast Asia is also firm tofu. This tofu, probably the original tofu transmitted from China to Japan, is the standard Japanese farmhouse tofu, firm enough to be tied into a package with rice-straw rope and carried without breaking. In tofu shops this tofu was gradually replaced by its softer (more watery) counterpart, which gave higher yields and higher profits, and which had a silken smoothness that many Japanese have come to prefer. In America it looks as if there will be a strong demand for both Chinese-style firm tofu and Japanese-style softer tofu. The firm, cohesive consistency of firm tofu allows it to keep its form well without additional pressing in the kitchen, making it ideal for use in sandwiches or salads as a substitute for cheese or ham, or in thick purees, such as dressings, dips, spreads, sauces, or soups.

Pressed Tofu. Called doufu gan ("dry tofu") in China, where it originated, this tofu is pressed under great pressure until its consistency is about as firm as that of cheese. It is also sold as Pressed Tofu Sheets (qianzhang or baiye), which can be sliced thinly to make Pressed Tofu Noodles (doufu si), or simmered with Five-Spice Powder to make Five-Spice Pressed Tofu (wuxiang doufugan). The first mention of the latter in the West was by Embrey and Wang in 1921. The spices were listed as cayenne, anise seed, dried orange peel, cassia bark, and star anise. After this?? first cooking it was oiled in black sugar residue (t'ang se??) to impart a dark color. Li (1912) and Adolph (1922??) discussed pressed tofu sheets. By the late 1970s, Quong Hop & Co. in San Francisco was making Five-Spice Pressed Tofu by simmering tofu in a seasoned shoyu broth then baking it. And China Bowl Trading Co. was importing a product that tasted like a spiced tofu jerky and came in pieces about 1 inch square and l/4 inch thick; they called the product Dried Spicy Bean Curd.

Smoked Tofu. Mention of smoked tofu in a Western publication first appeared in 1911 in Beltzer's "Extended Utilization of Soya Bean Products," in which he stated that in Annam (central Vietnam) one of the three principal varieties of tofu was a "cooked or smoked variety, which looks like Gruyere." Li (1912) made a smoked tofu in Paris. He cooked firm tofu in a mixture of 4 parts water and 1 part soy sauce, then smoked it as for meat and sold it wrapped in tin foil, suggesting that it be used in place of ham or bacon, as in omelettes. Smoked tofu was also discussed by Embrey and Wang (1921; the smoke was made by burning sawdust and the product was called yu kan or t'sai kan), Horvath (1927; it contained 17% protein), and Harris (1949; it was made in Chungking and served stir fried; it was very popular). In our travels in Taiwan and Southeast Asia we have never seen any smoked tofu.

In 1974 smoked tofu began to be sold commercially in Japan by the Meiji Foods Co. and Komatsugawa Tofu Co. Made from deep-fried tofu pouches stuffed with mashed firm tofu and seasonings, it came in three tasty flavors: mushroom, chestnut, and walnut. One 3.5-ounce piece, packed in oil in a sardine can, sold for about $0.65. The first Western research on smoked tofu was done by Pontecorvo and Bourne (1978); after 48 hours smoking, this tofu was given high taste panel scores and could be stored for 10 days at ambient temperature. As of 1981 we know of no smoked tofu being produced commercially anywhere in the world. Dolgin?? Yet this product has good prospects, in tropical countries because of its storage properties, and in the West because of its cheeselike texture and flavor.

Deep-fried Tofu. It is generally thought that deep-fried tofu originated in China (where it is called you doufu or zha doufu) but the history is unknown. Today most such tofu in China is prepared very simply by cutting firm tofu into either 1-inch cubes or 2.5-inch triangles and deep-frying it in one temperature of oil, or it may be cut on both sides in a special criss-cross pattern so that it forms a "net" after deep-frying. In 1899 Blasdale first mentioned deep-fried tofu in the West (San Francisco): "It is usually cooked in peanut oil and, in the author's opinion, is a palatable food."

The Japanese have developed three unique types of deep-fried tofu: cutlets, burgers and burger balls, and pouches. All three were first mentioned in the West in The Book of Tofu (Shurtleff and Aoyagi 1975).

Deep-fried Tofu Cutlets (Atsu-age, Nama-age). The Japanese probably learned how to make these from the Chinese, but the Japanese used a whole cake of tofu, pressed between bamboo mats then deep-fried to make a rectangular cake with a hearty flavor. By the late 1970s this was being sold in fashionable Tokyo restaurants as "Tofu Steak," topped with a thick, slightly sweet shoyu based sauce called tare. Quong Hop & Co. introduced tofu cutlets to the US in April 1978, although Japanese companies (Hinode, Azumaya) had sold similar products with Japanese names earlier. This product has great potential in America.

Deep-fried Tofu Burgers (Ganmodoki). In Japanese, ganmodoki means "mock goose." It is said that ganmodoki originated in Buddhist temples and monasteries during the 1400s. At that time, the latest, most expensive, and most sought-after food of the nobility was wild goose (gan). The story is told that when these freshly deep-fried creations were first served to the monks, they praised their flavor as surely being equal to that of the finest wild goose, and the new name was born. The addition of grated glutinous yam, a little salt, minced land-and-sea vegetables, and some sesame seeds to the well-pressed tofu before shaping into patties and deep-frying gave the patties an improved texture, flavor, and nutritional value. Deep-frying the patties first in medium temperature oil (170*C or 338*F) and then in a hot oil (195*C or 383*F) gave them a larger size and lighter texture. The first?? tofu burgers in North America were produced and sold in March 1977 at the Gilman Street Gourmet in Berkeley, California. In 1979 Quong Hop & Co. produced the first product distributed to retail outlets. Tofu burgers will surely become one of the most popular ways of using tofu in America.

A close relative, and probably an ancestor of tofu burgers are tofu burger balls or treasure balls, known in Japanese as hiryozu, which means "flying dragons' heads." Why? Because, for some reason, the process of deep-frying these balls causes the slivered vegetables to stick out helter-skelter from the surface like the bristling whiskers and spiky horns of Chinese sky dragons. In Kyoto, where these balls are most famous, the best varieties contain seven different vegetable ingredients, including ginkgo nuts and lilly bulb sections.

Although most scholars believe that tofu burgers and treasure balls were first developed by the Japanese, there are several other interesting theories concerning their origin. The first suggests that they were an adaptation of the Portuguese skewered meatballs (called hirosu) which also became popular in Japan during the 1400s. Since the Japanese word gan can mean "ball" as well as "goose" and since the names hirosu and hiryozu are very similar and are still used interchangeably to refer to Kyoto's burger balls, this theory seems quite plausible. The second theory suggests that tofu burgers were first developed by the Chinese, who still apparently prepare a similar type of deep-fried tofu containing ground meat instead of minced vegetables. This tofu, however, is not available at most Taiwanese or Chinese tofu shops.

Deep-fried Tofu Pouches (Aburage). It is generally thought that the Japanese developed tofu pouches, which are the most sophisticated of all tofu products in terms of complexity of the production. However little is known of their early history. The Tofu Hyakuchin of 1782 (Abe 1972) gave a recipe for deep-fried tofu, but it is not clear if it puffed up like a tofu pouch. It is known that tofu pouches existed by 1853, when Inari-zushi (tofu pouch filled with vinegared rice) originated (Ichiyama 1968). Because of their long storage life, light weight, and complexity of production, tofu pouches lend themselves to large-scale factory production and widespread distribution. By 1974 large factories were using 2 metric tons of soybeans a day to make 116,600 tofu pouches. By 1980 huge modern factories produced 300,000 to 450,000 pouches a day using conveyorized deep-fryers. At this time roughly one third of the soybeans consumed for tofu in Japan were for deep-fried tofu and an estimated 85% of this was for tofu pouches.

In the US the earliest known tofu pouches were developed by Azumaya, at least by the 1930s. In 1938, after the Mizonos took over the company, they developed a new type of tofu pouch that we call "deep-fried tofu puffs," because after deep-frying each one puffs up and stays puffed, resembling a golden and very light 2-inch-diameter, 4-inch long sausage. The inside is spongy and chewy. Hinode in Los Angeles started making regular tofu pouches in the 1970s.

During the late 1970s in Japan soy protein isolates were first used to make tofu for tofu pouches and burgers. Their advantages: high quality stability during frozen storage or dry storage. They were used in some instant dry noodle preparations.

An unusual relative of tofu pouches is Matsuyama age, which comes in light crisp sheets that are mild in flavor, golden brown in color, and about 6 by 8 by l/4 inch in size. Rich in protein (24%) and oil (64%), and very low in moisture (4.5%), it stores very well. It was first developed on Japan's island of Shikoku at the start of the Meiji period (1868-??). A famous maker is Hodoya Shoten, Doita-cho 499-1 in Matsuyama city. A similar product is made in Okinawa.

Grilled Tofu. As far as we know, grilled tofu (yaki-dofu) originated in Japan, since it is not found at all in present-day Taiwan or mentioned in writings on Chinese tofu. Some researchers think it was one of the earliest ways of preparing tofu in Japan. It probably originated at about the same time as Dengaku, which was first mentioned in the 15th century (1437). It also appeared in the Tofu Hyakuchin of 1782. Made from firm tofu, the earliest grilled tofu was skewered with two-pronged bamboo skewers (which in some cases were dipped into salt water to prevent burning) and grilled over a charcoal brazier using coals left over from heating the tofu shop's caldron. Country farmhouse tofu was sometimes skewered on a single 2-foot-long bamboo skewer, which was stuck upright in the ground near an open fire to grill the tofu. Grilled tofu has long been considered a food of the cold months and many tofu shops start preparing it each fall and stop each spring. It plays a key role in Sukiyaki and in Japanese New Year's cuisine (O-Sechi Ryori). In the mid-1960s the traditional charcoal brazier and skewers were gradually replaced by the system of laying firm tofu cakes on a bamboo mat and grilling them from above with a hand-held propane blow torch. In modern factories the tofu is placed on a motorized conveyor, where burners above and below the conveyor grill the tofu.

Grilled tofu was first mentioned in the West by Paillieux in 1880 in France. In 1982 in North America it was sold by only a few companies, such as Hinode in Los Angeles. Often grilled in restaurants, it was used nationwide in making Sukiyaki.

Silken Tofu and Pressed Silken Tofu. It is generally thought that the first silken tofu was developed in China. Called shui doufu, it was curded with calcium sulfate; nothing of its history is known. It is now produced by a few tofu shops in America.

The earliest Japanese silken tofu (kinugoshi) was a nigari silken tofu, shikishi-dofu, prepared in some 30-50 tiny wooden kegs, each about 4 inches deep, 4 inches in diameter, and coated inside with lacquer. Hot soymilk was poured into each container, nigari stirred in, and the tofu allowed to set. Details of the history are not known.

Beginning in 1703 a second form of silken tofu was developed at Tokyo's Sasa-no-yuki tofu shop and restaurant. The silken tofu was curded in 3.5 gallon wooden forming boxes. This tofu required great skill to produce and it was so delicate that it was hard to transport for sale; thus few shops made it and it was considered an aristocratic treat. Interestingly silken tofu was not mentioned in the Tofu Hyakuchin of 1782. This delicate nigari silken tofu is still prepared daily at Tokyo's famous Sasa-no-yuki and at a small but growing number of tofu shops around Japan.

Silken tofu made with calcium sulfate was developed in Japan by Dr. Umetaro Suzuki during World War II as described in detail above under Tofu in Japan (1940-59). Pressed silken tofu (softo-dofu) was developed after World War II as discussed earlier.

Lactone Silken Tofu. Lactone silken tofu was developed in Japan during the early 1950s and was quite popular by the late 1950s. It was based on glucono delta-lactone (GDL), a coagulant discovered in 1898 by Boutroux, while doing research on milk fermentation. In 1980 some 1,200 metric tons of GDL, made by fermentation of natural corn starch, were used for making tofu in Japan. The Japanese sometimes refer to all the different types of this tofu as juten-dofu ("filled tofu"), which they regard as basically different from silken tofu (kinugoshi), even though all are made like silken tofu without the separation of curds and whey to give the tofu a high yield and smooth texture. Since its development in Japan, and especially since the early 1970s in Japan, lactone silken tofu has rapidly increased its market share, since it can be produced by automation at a very low cost. We identify five types of lactone silken tofu, each with its own character and history.

Regular lactone silken tofu was made like regular silken tofu in forming boxes in small tofu shops, starting in the late 1950s. It was never widely used. In about 1968 an instant homemade tofu was marketed, consisting of a packet of spray-dried soymilk and a packet of GDL. In 1982 this was sold worldwide.

Bagged lactone silken tofu (fukuroiri-dofu), made and sold in sausage-shaped plastic bags, was developed in the mid-1950s and had become popular by 1958, as discussed earlier. The rapid growth in popularity of packaged lactone silken tofu after 1973 led to a decline in popularity of the bagged product. By 1982 it survived only in the northeast provinces.

Packaged lactone silken tofu (juten-dofu), by far the most popular and least expensive type, first started to be made in large modern factories in 1964 and started to become very popular from 1971-73 on. By 1978 the largest plants were making 70,000 cakes a day. All types accounted for about 10% of the total Japanese tofu market, and the market share was steadily growing. The average plant produced 30,000 cakes a day. In the early 1970s these manufacturers formed the Japan Packaged Tofu Association. By 1981 some 67 plants were making packaged lactone silken tofu, typically sold in 300-gram cakes in polyethylene packets.

Sealed lactone silken tofu (buro-dofu, the name comes from the blow-formed plastic container) comes in three flavors: peanut, almond, and egg. Sold in sealed thick polyethylene containers and having a 30-day shelf life, it was developed during the 1960s and became popular from about 1968. In 1982 production was increasing, especially among middle-sized tofu manufacturers. Large makers, such as Morinaga (which makes Sasa-me-yuki brand) have their output limited by a 1975 law designed to protect small tofu shops.

Ever-fresh silken tofu, sold in aseptic Tetra Brik cartons and having a shelf life of 6 months without preservatives at room temperature, was developed and patented in 1976 (US Patent 4,000,326) by Morinaga Milk Co. in Tokyo. After passage of the 1975 protectionist law mentioned above, Morinaga tried to find a new sales channel for its sealed lactone silken tofu by exporting it. But during shipping, the color browned slightly, so Morinaga set to work to develop the Tetra Brik product that could be exported. It was never intended to be sold in Japan, since the sealed silken tofu could be sold at a much lower price. However it is used on some Japanese ships. In 1978 Morinaga introduced the new Tetra Brik tofu to the international market, with emphasis on the US. In 1979 they came out with a new package design, the present product name, and a colorful recipe flyer as part of a strong sales campaign. By early 1981 some 72,000 cartons (each 297 gm or 10.5 ounces) a month were being made in Japan and sold worldwide; two thirds of this was in the US. The second largest market was the Middle East, where most was consumed by Japanese workers. Europe was third. Sales were increasing. We feel that this is an excellent product with great worldwide potential.

In 1980 Morinaga developed but did not market silken tofu flavored with vanilla, coffee, or strawberry, plus a yogurt silken tofu. Why not??

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History of Tofu - Page 7