Say Ohm: Japanese Electric Bread and the Joy of Panko

By Nathan Hopson

In 1998, the New York Times introduced readers to an exotic new ingredient described as “a light, airy variety [of breadcrumb] worlds away from the acrid, herb-flecked, additive-laden bread crumbs in the supermarket,” with a texture “more like crushed cornflakes or potato chips” than its plebeian brethren (Fabricant 1998). That ingredient was panko, which has since become a staple for American home and professional cooks alike. In 2007, panko accounted for only 3% of US breadcrumb sales, for instance. Five years later, one in six American households regularly stocked panko in the pantry. Panko caught on because it is crunchier (and stays crunchy under restaurant heat lamps), absorbs less oil, and adds more volume than traditional breadcrumbs (Nassauer 2013).

Why are these Japanese breadcrumbs different? How did they get to be that way? The story told by American manufacturers such as LA-based Upper Crust Enterprises―an ironic name given that the secret to panko is crust-free bread―is that “Japanese soldiers during World War II discovered [that] crustless bread made for better breadcrumbs as they cooked it with electricity from tank batteries, not wanting to draw the enemy’s attention with smoke from a fire”(Nassauer 2013). Upper Crust’s president, Gary Kawaguchi, affirmed this account in a recent interview.

This is a cool story. Turns out, the truth is just as cool.

Japanese inventors had tinkered with electric cooking prototypes since at least the 1920s. Then in 1933, the Imperial Japanese Army (IJA) commissioned a “field kitchen that can prepare both rice and bread”(Aoki 2019, 11). Cost was no object and time was of the essence. As Katarzyna Cwiertka has noted, the military generally advocated bread, but there was a special urgency in light of the logistical difficulties of supplying rice to new front lines in Siberia and Manchuria. In 1937, paymaster captain Akutsu Shōzō’s design became the “Type 97” field kitchen, first deployed with the IJA’s First Independent Mixed Brigade that year (Uchida 2020, 2–4). The 97’s cooker was an insulated wooden box with electrode plates attached to the base and four sides of the interior. The highly efficient cooking process Akutsu used goes by several names, including ohmic and Joule heating. It is a form of electroconductive heating that passes electric current through foods to heat them rapidly and uniformly, quickly producing a light, yeasty, crust-free bread.

Figure 1: Type 97 field kitchen interior structure. Courtesy of JACAR.

After the war, companies such as Sony began selling rice cookers and bread machines that adapted these wartime technologies, and DIY home bread makers were showcased in magazines and newspapers. Influential women’s magazine Shufu no tomo and the inaugural issue of boys’ DIY magazine Shōnen kōsaku both featured instructions for bread makers derived from Akutsu’s design in 1946, reflecting the popularity of electric power in light of consumer fuel shortages and, conversely, excess generating capacity with military factories shut down (Uchida and Aoki 2019, 484).

In the 1960s, the new postwar frozen food industry hungered for high-quality breadcrumbs. Wheat had poured into Japan after 1945, the result of food aid; the use of bread and other wheat products in Japan’s school lunch program; and endless marketing promotions. Although ambitious American visions to recenter the national diet on wheat were soon abandoned, US agricultural imports and food technologies remained critical to Japan’s changing postwar food systems. Improved and upscaled food processing equipment met a market awash in cheap wheat, enthusiastic consumers (about half of whom owned electric refrigerators by the mid-1960s), and improved logistics. Frozen foods were among the shiny new things of postwar Japan’s shiny new “bright life,” and the mass use of frozen foods to cater the 1964 Olympiad and 1970 World’s Fair made them even more attractive symbols of Japan reborn.

These factors spurred rapid growth in breadcrumb demand, which was met in large part by the industrial-scale use of ohmic heating to create “electric breads” that were airy and uniform, and fried up crisply and uniformly when made into panko (Uchida and Aoki 2019, 485).


Sources Cited

Aoki Takashi. 2019. “Denkyokushiki chōri no hatsumei kara panko e tsuzuku rekishi oyobi saigen jikken.” Science Journal of Kanagawa University, no. 30 (June): 9–16.

Fabricant, Florence. 1998. “From Japan, the Secret of Crunchy Coating.” New York Times, December 1998.

Nassauer, Sarah. 2013. “Panko Tries to Find a Place in Every Pantry.” Dow Jones Institutional News, March 7, 2013.

Uchida Takashi. 2020. “Suihan o kigen to shi panko seizō ni tsuzuku denki pan no rekishi (1): Rikugun suiji jidōsha to Kōseishiki denki suihanki to Takara ohachi.” Tōkyō Yakka Daigaku kenkyū kiyō, no. 23 (March): 1–14.

Uchida Takashi, and Aoki Takashi. 2019. “Suihan, denki pan, pan seizō ni itaru Nihon no denkyokushiki chōri no rekishi: Rikugun ‘suiji jidōsha’ o kigen to suru denki pan jikken.” Nihon Yakugaku Kyōiku Gakkai ronbunshū, no. 43: 483–86.


This post is part five in an ongoing series by Hopson on the history of nutrition in modern Japan. You can read his previous post here.

Tales from the Archives: Was There a Recipe for Korean Ginseng?

By Daniel Trambaiolo


As all of us continue to watch the COVID-19 vaccine rollout, and wait with cautious optimism for a time when we can heal and recover, I’d like to take a moment to revisit another medical breakthrough that required patience of its own. In this post from our archives, Daniel Trambaiolo recounts an exchange between a Korean and Japanese doctor as they “discussed” best practices for preserving and transporting the Korean wonder drug ginseng to Japan. I hope you enjoy our return to this tale of recipes, distribution logistics, and healing, no super-chilled storage freezers required.  -Joshua Schlachet


Ginseng_in_Korea

Ginseng, one of the best known drugs of the East Asian herbal tradition, can be purchased today almost anywhere in the world, but in the early modern period its availability was much more limited. The roots of Panax ginseng could be harvested only from its natural ecological range, in a region stretching across Manchuria, Siberia, and the Korean peninsula. In countries like Japan, where doctors relied on Chinese styles of herbal therapy but did not have direct access to herbal drugs that grew only on the continent, the roots had to be imported at high cost.

The cost of Korean ginseng became a source of concern in Japan during the final years of the seventeenth century, as the need to pay for the drug contributed to a steady outflow of Japanese silver that was used to pay for foreign products. During the early eighteenth century, the Japanese shogunal government encouraged doctors and herbalists to develop a domestic substitute, either by finding a native plant with similar medicinal properties or by discovering a way to cultivate Korean ginseng plants on Japanese soil.

Panax ginseng did not grow natively in Japan, but the related species Panax japonicus appeared similar and promised to have similar medicinal properties. However, the roots of the native Japanese species had a distinctive segmented appearance that led to Japanese doctors calling it “bamboo-segment ginseng”; their flavour was also more bitter and less sweet than the imported Korean product–a concern for many doctors, who believed that flavor was closely related to therapeutic efficacy. Some drug sellers claimed to possess secret methods that could transform the native herb into an equivalent of the imported drug, but how could these claims be evaluated?

Korean doctors were one obvious source of authoritative information on ginseng, but it was difficult to discuss the matter with them because the shogunal government had enacted strict policies limiting the movement of foreigners into Japan. Among the rare exceptions were the Koreans who travelled to Japan on diplomatic missions. Starting in 1682, these missions included a “medical expert” (K. yangǔi, J. ryōi 良醫) whose functions were to provide medical care for the members of the embassy and to allow Japanese doctors the benefit of Korean medical knowledge.

"KoreanEmbassy1655KanoTounYasunobu" by I, PHGCOM. Licensed under CC 表示-継承 3.0 via ウィキメディア・コモンズ - http://commons.wikimedia.org/wiki/File:KoreanEmbassy1655KanoTounYasunobu.jpg#/media/File:KoreanEmbassy1655KanoTounYasunobu.jpg
An early modern Korean embassy to Japan.

Neither the Japanese nor the Koreans could speak each others’ languages, so they communicated by writing down questions and answers in classical Chinese, a form of conversation known as “brush talks” (K. p’ildam, J. hitsudan 筆談). The records of these conversations were often preserved in manuscripts or books printed for wider dissemination, and they can offer us insights into the styles of cross-cultural communication that these embassies facilitated–as well as into the ways Korean and Japanese doctors tried to derive benefits from each other without giving away too much in return.

The following exchange on ginseng took place between the Japanese doctor Kawamura Harutsune and the Korean doctor Cho Hwalam during the Korean embassy of 1748. (The translation is based on the published version of their conversations, which was distributed by the prominent Edo bookseller Suwaraya Mohei.)

Kawamura: In our country there is a type of ginseng whose stem, leaves, flowers and berries are just as described in the Materia Medica; its roots are similar in shape to what Zhang [Zhicong] calls “bamboo-segment ginseng.” It is very bitter in flavor and unsuitable for use, so people customarily boil it with licorice root or process it with honey water. But although the bitter flavor departs and a sweet flavor emerges, it is not the original flavor.

However, my father found a processing method that is quite acceptable; it does not rely on the flavors of other drugs, but the bitter flavor departs and a sweet flavor emerges. When my father consumed [imported] ginseng, he would always see blood in his phlegm. When he consumed the ginseng that he had processed himself, he would also see blood in his phlegm. Looking at it this way, is its efficacy similar to the ginseng from your country?

Cho: While I was in Osaka, I already heard people talk about your country’s ginseng. Although when you see the stem and leaves it looks similar, after tasting its flavor and inspecting its form it is clearly not genuine. You can perform all sorts of marvelous transformations to alter its bitter flavor, but how could you use it? There is no method for processing ginseng: you should use it just as it is naturally. Don’t be confused about this!

Kawamura: Your explanation is sufficient to dispel doubts. However, among several pounds of ginseng from your country, some roots have a burnt yellow color and seem to have undergone processing. Moreover, during [the embassy of] 1711 the Korean doctor Ki Tumun transmitted a processing method to a disciple of my grandfather. However, the paper has been eaten by insects and is now difficult to read. I will briefly write it down here, but I beg you to enlighten me further.

[Thereupon, he told me the method for processing ginseng. It is marvelous, and I have submitted it to the authorities. I do not record it here, but I have recorded it elsewhere and keep it in my home.]

Unfortunately, there are no surviving records of what Cho transmitted to Kawamura, so it is impossible to know whether it was a genuine recipe used by Koreans for processing ginseng or merely one he invented on the spot to deflect Kawamura’s questioning. Kawamura may have decided to omit the recipe from the published version of the brush talks in order to profit by selling ginseng processed according to a “secret Korean recipe.” However, his opportunities for doing so would probably have been quite limited. A few years before the meeting between Cho and Kawamura took place, a different group of Japanese herbalists succeeded in cultivating Korean ginseng from seedlings smuggled into Japan from Korea. As this new source of cultivated ginseng became commercially viable, the demand for “processed” ginseng dwindled rapidly and the recipes for such processing were gradually forgotten.

Meals on Wheels: The “Kitchen Cars” and American Recipes for the Postwar Japanese Diet

By Nathan Hopson

From 1956 to 1960, the USDA Foreign Agricultural Service (FAS) sponsored a fleet of food demonstration buses in Japan (“kitchen cars”) to improve national nutrition and fuel the nation’s economic recovery with more “modern” and “rational” cooking methods and, most importantly, ingredients (i.e. American agricultural surpluses: wheat, corn, soy, and to a lesser extent meat, dairy, etc.) The concept was first floated to the US by Dr. Ōiso Toshio, chief of the health ministry’s nutrition section, 1953-1963. Along with the school lunch program instituted under the US occupation, the kitchen cars became one of the most important tools for marketing American farm products in Japan. The school lunch program, centered on bread and (reconstituted skim) milk until the 1970s, taught young Japanese new tastes. The kitchen cars taught their mothers to reproduce those flavors at home.

The initial fleet of a dozen buses, operated by the Japan Nutrition Association (a semiprivate organ of the health ministry), reached over two million people in towns, villages, and apartment blocks across Japan. The nutritionists staffing the buses put their professional imprimatur on the many novel foods they demonstrated, and distributed samples, nutritional pamphlets, and the day’s recipes to their audiences of mostly housewives. The kitchen cars were wildly popular. When US funding expired, local Japanese governments built their own to meet public demand; the number exceeded 100 by the end of the 1960s. Though it is difficult (impossible?) to quantify, the kitchen cars contributed in subtle but profound ways to transforming the postwar Japanese diet.

Despite their popularity at the time, today the kitchen cars are mostly forgotten. When they are remembered, it is mostly for destroying “traditional” Japanese dietary patterns and contributing to the “Westernization” of the diet during the period of high economic growth. This backlash stems in part from the fact that American financing was hidden not just from the public, but also from all those who staffed or assisted with the kitchen cars. Still, in the short run, these buses were a win-win for the US and Japan. America’s Cold War “Food for Peace” campaign put agricultural surplus to work supporting a critical ally, and Japan received enormous amounts of free or cheap food and generous development loans.

Figure 1: Kitchen car demonstration in rural Aomori, year unknown (probably 1950s). Courtesy of the Aomori Prefectural Museum.

The photo above shows a typical scene from a day in the life of the kitchen car. The audience crowds around the back of bus, which opens up like a thrust stage for the nutritionists to perform upon. The gathered women listen intently, some taking notes. The kitchen installed in the rear of the bus is the state-of-the-art chrome and gadgetry emblematic of the new postwar “bright life” of happy consumerism. The nutritionists in their white lab coats bring the authority of science. The foods they are preparing may not seem like the stuff of American farm surplus propaganda, but as Ōiso himself observed, “Propaganda is truly effective when people don’t notice it.”[1] To wit, the noodles are most likely soba: buckwheat mixed with (American) wheat. Even subtler is the use of sautéing, undoubtedly in (American) corn or soy oil. This kind of gradualist approach, expressed in slogans such as “Flour-based food once a day,” helps explain both why nobody suspected American involvement and why the kitchen cars were so popular and effective.

Few detailed records of 1950s’ kitchen car menus remain, but those that do are consistent with accounts from the 1960s. A list of favorites from mid-decade Okayama prefecture includes milk donuts, udon stew, sautéed amaranth leaves with liver, fried meat and vegetables with ketchup, vegetable cream soup, fried soybean fritters, chicken and peanuts in tomato sauce, bok choy with peanuts and mushrooms, and cheese sponge cake. Roughly simultaneously, the prefecture’s public health center sponsored competitions for original, tasty, nutritious, economical foods (about ¥20 each) using ingredients like soy, skim milk, and flour. Winners included vegetable omelets, fried tofu-wrapped sardines, fried sardine balls, and mysterious entries such as “nutritional bread” and “nutritional fried dumplings.”

These lists lend credence to the remarks of Richard Baum, Ōiso’s initial American collaborator. In a 1978 documentary, Baum expressed immense satisfaction at the kitchen cars’ success. As he explained, “the housewives would come out and gather around and learn how to make different wheat foods. And then they would get to sample the wheat foods. And they found these very delicious and so they would say ‘Oishii desu. Mō sukoshi’ [This is delicious. A little more, please].”[2]


[1] Quoted in Takashima Teruyuki, Amerika komugi senryaku: Nihon shinkō (Ie no Hikari Kyōkai, 1979), 106.

[2] Quoted in Takashima Teruyuki, Shokutaku no kage no seijōki: kome to mugi no sengoshi (NHK, 1978).


This post is part four in an ongoing series by Hopson on the history of nutrition in modern Japan. You can read his previous post here. This entry is based on his article “Ingrained Habits: The ‘Kitchen Cars’ and the Transformation of Postwar Japanese Diet and Identity.” Food, Culture & Society, November 2020.

Colouring metals in the Far East

By Agnese Benzonelli

How far can someone go in the name of research? In my case quite a long way. For a month, I loosely taped tiny plates of metal to my hands and woke up every morning with green stains on them. I was investigating craft recipes employed in the far East since the fourteenth Century to create coloured metal and alloys used for beautiful small artefacts. Whereas Western taste preferred the natural colour and the polished lustre of metals, the Eastern preference was to use the process of chemical patination, where different chemicals react with the surface of copper and copper alloys to form new coloured compounds.

Fig.1: Left: a tsuba (handguard of Japanese sword) made of shakudo and gold; BM-TS244. Right: a Chinese gu-tong box; BM-1992,1109.2. Photos made by A. Benzonelli.

The Japanese created a whole class of coloured alloys, called irogane. They added small amounts of different elements to the copper and simmered it in a solution containing copper salts, alum, vinegar and other ingredients, to form coloured patinas on the surface. The most beautiful patina, shakudo, was made with copper and gold and achieved a deep blue-black colour. Combining a variety of alloy compositions and solution ingredients, they were able to create hues ranging from pale brown to black. Inlaying different irogane, gold, silver, and lacquers, they were able to create small artefacts and swords fittings with complex and visually impressive designs and patterns.

Fig.2: Picture of the 13 Japanese solutions created and tested taken from Japanese recipes reported in Eastern books.

Later on, Chinese craftspeople imported the technique from Japan, possibly through travellers or trying to copy the Japanese artefacts, and, from the Ming period (1368-1644), they used it to colour ink or tobacco boxes. In contrast to the Japanese irogane, the Chinese would patinate a gold-silver alloy only, which resulted in a dark colour similar to that of shakudo, which they called gu-tong. In both cases, the precious metal content was 1-3%, a larger amount would not affect the final patina colour.

There’s not a lot known about the two different recipes the Chinese craftsmen employed to produce their patinas. However, we do know that one process they utilised was similar to that used by the Japanese to produce the irogane,butwe have no precise recipes for the solutions. Another involved handling the metal until the perspiration from their hands corroded the surface.

Creating and play with metal colours has always fascinated me. Why using gold and silver to achieve that dark colour, instead of cheaper alternatives? What was the role of the different ingredients used in the recipes? Could sweat really be used as a patinating solution? Why did Japanese recipes tell not add precious metals to bronze (copper alloyed with tin) but only to pure copper? Could it be confirmed through scientific analysis that the technology was really transmitted from the Japanese to the Chinese culture? To find answers, I needed to conduct a systematic experimental research which could explain the reasons behind the technological choices of Japanese and Chinese craftsmen.

 I reproduced a series of alloys with tin, gold and silver, which I then patinated, following the recipes for shakudo and gu-tong from available texts. These are not numerous, as the recipes were mainly kept as secret and passed from father to son. We have city records, information sheets given by dealers and, in Japan, technical texts on metal working. I analysed the resulting patinas with techniques borrowed from modern material science, and used the experimental data as reference for the interpretation of historical patinated artefacts in museum collections.

I found that, for both the Japanese and Chinese recipes, the presence of gold in the alloy did, in fact, change the colour of the final patinas, which resulted in a better, more uniform and darker hue. I also noted how parameters such as the fine grade of surface polishing prior to the patination, the use of tin-free alloys, the selection of copper acetate as a main ingredient and the addition of vinegar are all processes and actions that led to a reduced patina growth. And as it turned out, sweat was indeed an effective patinating solution in the Chinese patination (as it can be noticed by the green corrosion products left on the hands), but the presence of gold in the alloy composition is nonetheless essential to obtain a dark hue, not achieved in gold-free alloys. Sweat is a slightly acidic solution, similar to that of used by Japanese craftsmen, essential to create a coloured copper oxide on the surface in just 48 hours of handling. Similarly, in both technologies cleaning of the alloy before or after the procedure suggested in Japanese texts and the abrasive action of the hands in the Chinese method are both similar and crucial steps in the patination process. I concluded from these findings that a dark patina was not the only feature that the craftsmen of both cultures had been striving for. They also seemed to be after a shiny appearance, given by the metallic lustre coming from the alloy.

Fig. 3: Alloys of different compositions patinated with Chinese patination.

In combining experimental and historical observations I gained an understanding of the intentions behind the technological choices made by the Japanese and Chinese artisans. My analysis confirmed the deliberate nature of these choices made to achieve dark and shiny blue-black colours otherwise impossible. This confirmed the importance of colour as a driver of these artisanal processes, and supports the idea that the knowledge was transmitted between the two cultures.

Was it worth in the end – the green hands and other discomforts suffered in the name of research? It was the first study to provide a scientific basis to our knowledge of the methods and choices made by those people, the ingredients they employed in making dark patinated artefacts, and contributed to our pool of knowledge of the artisanal methods and practices described in historical sources. So yes, it definitely was, and I would definitively do it again.