Imported Sugar: 1569-1689

Until the end of the seventeenth century, Japan was on the consuming end of global trends in sugar production. In 1569, Portuguese missionary Luís Fróis gifted konpeitō, sugar candy, to warlord Oda Nobunaga as part of attempts to gain permission to spread Christianity.Footnote ⁵ Contact with Iberian foodways in the sixteenth century created a demand for sugar to be used in recipes, confectionary, and baked goods, such as kasutera – a moist Portuguese sponge cake that became a speciality of Nagasaki – disseminated through texts such as the Southern Barbarian’s Cookbook (Nanban ryōrisho).Footnote ⁶ After Japan limited trade in the 1630s, this need was met primarily by muscovado (brown, unrefined or partially refined sugar), white sugar, and rock candy imported to Nagasaki by merchants from Guangdong, Fujian, Taiwan, and what is now Vietnam, as well as smaller quantities from Dutch Java. For example, in 1641, 97 Chinese ships, including 89 from Fuzhou, brought 2,546,427 cattiesFootnote ⁷ of sugar, almost entirely muscovado, to Nagasaki along with 5,427 catties of white sugar.Footnote ⁸ The same year saw Dutch East India Company ships, the only Europeans allowed even a limited trade with Japan at that time, bring 35,000 catties of muscovado and 4,000 of white. In addition, three ships from Quảng Nam, today’s central Vietnam, brought 4,000 catties of muscovado and 20,000 of white.Footnote ⁹ The Dutch sources in 1652 conceded that sugar sold to Japan barely made a profit, since the trade was dominated by the Chinese traders who also used sugar as ballast.

Import Substitution: 1689–1800

Japan was a major exporter of gold, copper, and especially silver throughout the seventeenth century, and this trade was boosted once Qing China relaxed its overseas trade policies in 1684. Some leaders and intellectuals in Japan regarded this outflow of metal as a crisis.Footnote ¹⁰ In response, the bakufu restricted imports into Nagasaki. Meanwhile, domestic demand for sugar continued to increase. Osaka doctor Terashima Ryōan, who wrote the Illustrated Sino-Japanese Encyclopaedia (Wakan sanzai zue) in 1712 described 2,500,000 kin of sugar arriving annually in Nagasaki and ranked it from highest to lowest quality according to its origin. The best quality, apparently, was that from Taiwan, followed by sugar from Jiaozhi, Vietnam, then Nanjing/Fujian/Ningbo. Sugar from Batavia, imported by the Dutch, was the worst.Footnote ¹¹ At this stage, it was still unlikely that ordinary Japanese could get their hands on expensive, crystallised sugar imports. But with Japan’s peace and increasing prosperity, consumers were able to purchase sweets and sugar for food products such as manjū buns, plum wine, preserved fruits, and sugar water. The mix of rising consumer demand and restricted imports created a situation in which, over the rest of the Edo period, Japan built up its own domestic sugar industry, split equally between two separate technological and developmental pathways: mainland sugar, promoted by the shogunal government and dominated by the white sugar industry of eastern Shikoku, and an earlier path of muscovado produced in the Amami islands and exported by the Satsuma Domain. The latter sugar industry increasingly took on familiar features of early modern planter colonialism, in which the governing class of Satsuma administrators, though a minority, exerted political, legal, and administrative control; maintained distinct markers of identity from the local populations; and established large-scale monocultures for export to metropolitan markets.Footnote ¹² It is important to note, however, that the sugar farmers, while many of them working in conditions of debt bondage, were Amami islanders and not an imported labour force, as was seen in many sugar-producing areas such as the Caribbean.

Satsuma’s Sugar Islands: The Amami Archipelago

Until 1609, the Amami islands, consisting primarily of the islands of Amami Ōshima, Kikaijima, Tokunoshima, Okinoerabujima, and Yorontō, formed the Northern Cultural Zone of the Shuri empire (see Figure 1).Footnote ¹³ After 1609, the Amami islands were referred to as Michinoshima (Waypoint Islands). In good weather, it was possible to navigate by boat between mainland Satsuma and Okinawa using islands as waypoints, one always being visible. The roughly four hundred kilometres of rough seas between the northern point of Okinawa Island and Takarajima, the southernmost island of the Tokara chain, were not only regularly traversed by a wide variety of agents of different political statuses and loyalties, including exiles, wayward foreign ships, embassies, samurai officials, smugglers, and merchants, but were also inhabited by up to ninety thousand Amami islanders.Footnote ¹⁴ With the import of sugar-making technology in 1689–91, these islands were to become a sugar laboratory, factory, and colony of the Satsuma Domain.

Figure 1.

The Amami Islands within the Satsuma Domain. Map by author, based on Google Maps.

The Keichō Period Theory of Technology Transfer

Histories of technology transfer, like other narratives that seek origins and moments of breakthrough, can be subject to local and national desires for honour, prestige, and even financial reward. In the Meiji period there emerged a theory that sugar arrived in the Amami islands in the Keichō period (1596–1615), brought to Amami by an islander called Sunao (“Honest”) Kawachi. According to this widely repeated theory, Kawachi was shipwrecked in Fujian around 1610, learned how to make sugar, and smuggled back cane seedlings in a modified bag which he successfully cultivated in Yamato village, Amami Ōshima. The Kawachi family submitted this history for a sugar and cotton exposition in Osaka in 1880, for which the family received one hundred yen from the Ministry of Finance, and a shrine in Yamato village was built in their ancestor’s honour with donations from across the island. This theory was repeated in history books such as Amami shidan (1903) and as recently as Amami Ōshima shi (1984). In 1964 the Japanese government promoted the deified Kawachi to Junior Fifth Rank status (jugoi), and the shrine was rebuilt in reinforced concrete.Footnote ¹⁵

It is possible that an ancestor of the Kawachi family was involved in the transfer of sugar technology, but not as early as 1610 or in the manner described for the 1880 Osaka exposition. The first to question this theory was folklorist Iwakura Ichirō (1904–43) from Kikaijima. Iwakura pointed out that a Ming embassy to Ryukyu in 1534 noted sugar, along with banana, pomegranate, citrus, and types of persimmon among Ryukyu’s main crops. If sugar cane was being grown on Ryukyu, it was probably already a familiar crop on Amami, even if it was not processed into sugar crystals. Furthermore, Sunao Kawachi was said to have successfully produced one hundred catties of sugar in his first year from the cane seedlings he smuggled back from China in a modified bag. Iwakura calculates that in that period, newly planted cane seedling could produce thirty catties of sugar per one hundred square metres. To produce one hundred catties, Kawachi would have needed to bring back enough cane to cover over three hundred square meters of land – an implausible amount to bring back, clandestinely or otherwise.Footnote ¹⁶

The Keichō theory lost further credibility in 1965 when the archival team compiling the local history of Naze town unearthed an 1866 document from the Nigi household. This document described how in 1689 an ancestor of the Nigi accompanied the inspector of Yakiuchi district, also Kawachi, to Ryukyu to learn sugar making. They successfully trialled growing sugar cane back on Amami, and it quickly became a major crop. Nigi and Kawachi were both recognised in writing by the island governor for their service.Footnote ¹⁷ Governor’s records from Amami Ōshima also first note the appointment of cane inspectors on Amami Ōshima and Kikaijima in 1695.Footnote ¹⁸ Somehow, these records were ignored or unknown when the Meiji government sought to narrate the arrival of sugar making to the Japanese islands. The myth of Sunao Kawachi is perhaps indicative of a need to emphasise continental, rather than Okinawan/Ryukyuan, roots for technology at a time when Okinawa’s recent absorption into the Meiji state and its status, history, and identity as both “non-Japanese” and “backwards” was highly contentious.Footnote ¹⁹ It is an example of how local and government interests can narrativise histories of technological transfer according to their interests, and how such stories can seek an entrepreneurial hero at the expense of more complex and less spectacular histories of imitation, experimentation, and incremental rather than revolutionary advance. A further complexity elided in the Keichō theory is the Amami Islands’ specific geopolitical position since 1609, governed by a Japanese domain but remaining part of the Ryukyuan world and presented as such by Satsuma. Thus, Amami’s promotion as the origin of Japan’s sugar industry in 1880 is tied to the complexity of Okinawa’s status in the Meiji period.

Nonetheless, it is notable that Ryukyu and Amami had advanced sugar-making technology decades prior to the rest of Japan. In the seventeenth century, Ryukyuan sugar technology experienced a micro-revolution, and this technology continued to develop as it adapted to conditions on the Amami islands. Evidence of sugar in the central and southern Ryukyu islands can be found as far back as 1429, but the technology there remained basic until the introduction of Chinese two roller mills in 1623, likely facilitated by the community of Chinese scholars in Kumemura, and the invention of the three-cylinder mill in 1673.Footnote ²⁰ By reducing the amount of labour required, the latter was a transformative technology and one of a few recorded independent inventions of the three-cylinder mill outside of its first appearance in Spanish Peru and Brazil in the 1610s.Footnote ²¹ Sugar technology arrived on the Amami islands at a relatively advanced stage.

Officials and farmers on Amami continued to innovate. In 1717, Tabata Sabuni harnessed the cane rollers to a water wheel, at least doubling the rate at which the rollers could crush cane juice. This technology was later copied and modified in the rest of Japan, as seen in a 1797 sugar manual, Satō seisakuki.Footnote ²² Waterwheels were used sporadically on Amami in the wet season. In 1808, Kashiwa Yūto replaced wooden rollers with longer-lasting and more precise iron-capped rollers. Kashiwa also experimented with five- and seven-roller mills, thirty-two years before the first such patent in Europe.Footnote ²³ Amami was small geographically, and the size of its sugar industry paled in comparison with that of southern China or Caribbean islands such as Cuba, but it was nonetheless a site of active technological innovation.

The Expansion of Sugar Production on Amami

Having been established in the 1690s, sugar production took off within a few years. The consequent demands on labour and the environment saw administrative changes as the islands started to transform into sugar factories. Satsuma first sent cane inspectors to the islands of Ōshima and Kikaijima in 1695, and in the same year chieftains from Kikaijima requested several large pots for sugar boiling and processing. In 1698, Satsuma sent to Ōshima a wave of new officials; along with those appointed to oversee specific regions of each island, the domain also sent administrators to oversee specific economic activities, including cane, bamboo/trees, harbours, and rice paddies.Footnote ²⁴ By 1713, the Amami islands were already producing 1,130,000 catties of sugar annually. In 1726–28, however, the domain carried out a survey on Amami and decided to lay greater emphasis on rice production, encouraging fields to be turned into rice paddies, inspecting the quality of rice, and appointing inspectors to oversee rice planting, along with policies restricting islanders from growing sugar cane without permission.Footnote ²⁵ Even by the mid-Kyōhō period (1716–36), therefore, the driving force behind the spread of sugar cane came from islanders themselves, presumably finding sugar a useful good to be traded with the merchant ships that arrived periodically; the domain and its officials remained wary of sugar cane, with its potential to distract from and crowd out the rice production that was essential for subsistence. Despite powerful economic incentives, the sugar industry did not develop linearly in response to market demand.

Sugar production continued to steadily increase, with the domain purchasing 3,500,000 catties of sugar from Ōshima in 1745. In that year, Satsuma decided that Ōshima’s tax burden be fully converted from rice to sugar. The neighbouring island of Tokunoshima, however, began to struggle. In 1755, a terrible harvest led to severe famine on the island, in which over three thousand people died of starvation. The island requested emergency rice from Kagoshima, but Satsuma’s delivery was late and Tokunoshima received rice from Ryukyu instead, with officials openly criticising Kagoshima in their report.Footnote ²⁶ This catastrophe was partly caused by sugar cane replacing rice and grains. From 1756 two Satsuma inspectors led a project to accelerate sugar production on Tokunoshima, achieving over one million catties by 1759. The spread of sugar cane, a cash crop of little nutritional value, and its replacement of food staples such as rice and millet had caused an ecological rupture; the islands became increasingly dependent on exogenous sources of food, as well as local adaptations such as sweet potato and starch from cycad bark.Footnote ²⁷

After a failed attempt to enforce a monopsony over sugar production in 1777–87, Satsuma established a total monopsony, purchasing all sugar produced by the islanders, beginning in 1830 and lasting until 1878. Burdened by growing debt to Osaka merchants, Satsuma tried to redirect sugar profits from its own merchants to the domain by forbidding private trade to the Amami islands, and requiring each individual islander of adult age to produce a quota of sugar, with surplus used to purchase food and imported goods. Sugar production led to deforestation of the landscape and the terracing of hillside plots, while firewood imports from other islands met the need for fuel, mainly to boil the sugar. Sugar being property of the domain, officials delivered severe punishments for any infringements, up to the death penalty for stealing sugar and trying to sell it privately.Footnote ²⁸ In order to cope with food insecurity, islanders invented a method of boiling down the toxic flesh of the sotetsu cycads found around the island for sustenance. Islanders who could not grow enough sugar, such as those growing on land close to the sea subject to a salty breeze and typhoon winds, found themselves struggling to survive, and thus sold themselves into bondage to households in a more comfortable position.Footnote ²⁹ A new hierarchy developed, including an underclass of indebted labourers who came to be called yanchu. Households traded yanchu, whose children inherited their underclass status.Footnote ³⁰ While the proximate origin for sugar technology and knowhow in Japan was Ryukyu and China, the scale and monoculture of the sugar industry that emerged in the Amami islands and the ways it transformed the environment and society were without parallel in the rest of East Asia.

A Samurai Exile’s Journal, Nantō zatsuwa (Tales of the southern islands), 1850–55

A rich source of evidence about the sugar system and other details of life on Amami is contained in the journal of Nagoya Sagenta, an upper-level samurai exiled to the islands in 1850. Calling his journal Nantō zatsuwa (Tales of the southern islands), Sagenta recorded, with an anthropological eye and artistic hand, religious traditions, foodways, and various aspects of Amami society that he most likely, as a Satsuma man, found wholly unfamiliar. Among his illustrations are a rudimentary but effective system of producing brown sugar. Based on this and other sources, the method of producing sugar on Amami was relatively simple but involved several steps; the need for fuel, skilled oversight, and the continuous operation of mills during the harvest season elevated sugar making to an agro-industrial process. Once cut, cane had to be squeezed and its juice processed within a day or two before it rotted. Farmers would feed the cane through a roller powered by oxen or a waterwheel, collect the juice in oblong pots, and boil it above a furnace fed with firewood. The existence in illustrations of several of these pots, although few in number, show a process of boiling sugar at different temperatures to avoid caramelisation and achieve crystallization. Lime would be added from sources such as coral, bringing out impurities that were then removed from the mixture. The viscous liquid would be poured onto a flat tray and allowed to cool. The resulting crystallised sugar is light brown in colour and has a grainy, even chewy or crunchy texture.Footnote ³¹ Around 1800, attempts were made to produce white sugar on Amami using methods learned from Shikoku, but the governor of Ōshima, Honda Magokurō, advised the domain that the extra steps involved in the process consumed too much time and labour to be cost effective.Footnote ³²

Sugar bound for the domain was stored in wooden barrels, then checked and measured by officials. Sources do not reveal the state of the sugar when it was placed in the barrels, but these barrels had to be well made to support the heavy mixture or crystals.Footnote ³³ Researcher Mio Arao suggests that a clue may lie in the following sixteen-syllable poem from the Edo period:

This suggests the black sugar, most likely from Amami, was hard and compact enough to stand on its own having been tipped out of the barrel. Shops in Japan’s large cities such as Kyoto and Edo would have displayed this sugar in barrels or placed in the open, like the miniature Mount Meru of the poem, as one of their most valuable goods. This process, from cane to store, was how the Amami islands supplied cheap sugar for the growing early modern Japanese economy, ultimately shaping culinary tastes and social habits.

Technology on the Mainland: Shikoku’s Household Sugar Industry

While this sugar history was unfolding on Japan’s southern islands, another sugar economy on the mainland was following a divergent technological path, producing a different product, and concentrated on the northeastern corner of Shikoku. The shogunate and other domains gained knowledge of sugar production via two channels: imported Chinese agricultural manuals and piecemeal information from Amami and the Ryukyus, jealously guarded by Satsuma.Footnote ³⁵ First attempts to grow sugar more widely in Japan came under the enterprising shogun Tokugawa Yoshimune. In 1727, Yoshimune’s shogunate was able to procure cane seedlings from Ryukyu and plant them in Fukiage medicinal garden near Edo castle, producing sixty catties of sugar.Footnote ³⁶ The climate in the Kantō plain, however, made sugar cane growing difficult. As Christian Daniels has argued, the absence of Chinese engineers accompanying the spread of Chinese sugar technology both delayed the success of Japan’s sugar industry and incentivised local entrepreneurs and innovators to adapt.Footnote ³⁷ It would take several decades before the shogunate tried again, but by the end of the eighteenth century, Japan’s mainland sugar industry had found success.

Innovator Ikegami Tarōzaemon

In the 1760s, the shogunate tasked Ikegami Tarōzaemon (1718–98), a village headman living near Edo who was part of a group of scholars practicing natural history (honzōgakusha), with conducting experiments in growing sugar cane.Footnote ³⁸ Ikegami was primarily interested in land redevelopment, and had experimented with diverting the silt carried by rivers to create new arable land.Footnote ³⁹ The shogunate, at this time wanting to renew investigations into the sugar industry, pressed him to devote his energies to growing sugar cane using cane shoots acquired from the Ryukyus.Footnote ⁴⁰ It was unclear whether he enthusiastically embraced this new project, but his household documents record multiple meetings and concerns that suggest he may have been reluctant.Footnote ⁴¹ Growing the seeds on his reclaimed plot of land near the sea was a total failure, and he guessed, presumably correctly, that the salt levels in the land were too high for the cane to grow.Footnote ⁴² His team found better success growing the cane in the hills. This process of trial and error continued until in 1764 he reported success in growing cane and making a passable sugar from it. Ikegami was keenly aware of the purpose and significance of these experiments: he repeatedly mentioned his hopes that the cash crop would benefit the country economically and be a boon to peasants, domains, and the shogunate.Footnote ⁴³ In this he was correct: by 1780, twenty-one villages in the Kantō region were producing millions of pounds of sugar at a huge profit of over 500,000 ryō.Footnote ⁴⁴

The sugar industry gave the relatively small Takamatsu Domain, which became the largest producer, a valuable export good that helped it to weather the debt crises faced by many other domains in the first half of the nineteenth century. Meanwhile, its neighbouring rival, the Tokushima Domain, specialised in fine grain sugar used for confectionary, later given the name wasanbon, to be made into high-quality decorative sweets often given as gifts or served with green tea in formal settings. To differentiate their product from unrefined Amami brown sugar and other types of white sugar, producers in Shikoku created a distinctive texture by adding an extra stage of pressing the molasses from the unrefined sugar with a heavy weight. The machine they used for this – called an oshifune – had been adapted from soy sauce and sake brewing.Footnote ⁴⁵ Already by the beginning of the Tempō period (1830–44), the Takamatsu Domain was producing 61.2 per cent of the sugar sold in Osaka, from where it was shipped around the entire country. Eastern Sanuki was the most productive part of the region for sugar, with over eight hundred mills recorded in the 1820s, almost a third of the total number of mills in the wider Sanuki Province.Footnote ⁴⁶

The rapid development of this industry transformed the countryside in both Sanuki province and Tokushima, offering farming households and villages a way to engage in producing a lucrative cash crop. By the Keiō period (1865–68), there were 5,500 pressing machines in the Tokushima Domain. Assuming that each machine was manned by roughly four people – two to operate the rollers, one to lead the oxen, and one for miscellaneous tasks – the industry may have involved around 22,000 people. In addition to each pressing machine, the various other processes involved in sugar manufacture also required labour, from cleaning the boiling pans and supervising the thickening of the sugar mixture to refining the mixture into white crystals. The Takamatsu Domain exploited this process to gather tax revenue from all sugar exported to the market in Osaka, applying taxes to the growing of cane in the field as well as the buying and selling of the final product. In addition to its managing of Japan’s largest salt field in Sakaide, white sugar was extremely valuable to the domain. When the domains were abolished in 1871 and their assets handed over to the Ministry of Finance, the Takamatsu Domain reported considerable assets of over one million yen.Footnote ⁴⁷

The Tokushima Domain rivalled Takamatsu’s dominance with a rapidly developing sugar industry of its own and a higher quality product. The technology used in Tokushima was most likely transferred over the low mountains that separated the two provinces despite various human and natural barriers.Footnote ⁴⁸ The spread of this technology was no doubt helped by a system called karikoushi in which farmers from Sanuki Province would borrow oxen from Tokushima for their farming, and in exchange allow Tokushima villagers to use their sugar mills. This local system smoothed the way for the flow of new information and other technology in a political system that otherwise tried to limit mobility. Tokushima’s most valuable export commodity was indigo, but porous boundaries, economic competition, the existence of skilled craftsmen or engineers, and a shifting intellectual context that increasingly encouraged domains to specialise in export goods created a surprisingly open environment to rapidly develop sugar-making technologies.Footnote ⁴⁹

Claying and Pressing Methods

Unlike in Satsuma, the shogunate learned the Chinese “claying” method of refining brown sugar with the moisture of wet soil placed on top, producing white sugar. The documents of Ikegami and other natural scientists mention the “covered-claying” method, in which clayed soil was placed on top of a jar of unrefined sugar and left for moisture to separate molasses from the white crystals. There is little evidence of other methods until the 1830s, when the pressing method, described above, appears. Claying and pressing were the principal methods for refining sugar crystals until around 1880, when they were superseded by newer methods and Japan’s sugar industry was exposed to global markets.Footnote ⁵⁰ It is said that the doctor Tamura Ganyū discovered the covered-claying method when, using Chinese manuals as a reference, he placed soil dried in an oven on top of the sugar and discovered that the sugar underneath eventually turned white. Thereafter, Ikegami himself experimented with wet soil and found that the water content of the soil more effectively removed impurities as the sugar dried in its cone-shaped container. From their records, many of these early scientists experimented with different types of soil for claying, such as soil found at the bottom of rice paddies, and tried adding materials to the soil such as “medicine” (a vague term, but can encompass various plants and herbs) and even vinegar.Footnote ⁵¹

The covered-claying method remained an imperfect process, however. Producers complained that the crystals would form at the bottom of the sugar cone and the impurities would gather at the top, making them difficult to scoop out. In addition to paying greater attention to the quality of sugar cane, the purity of the sugar cane juice, and the boiling process, growers also sought a means of obtaining white sugar crystals without having them sink to the bottom and having to separate them from the impurities. In addition, when the impurities are particularly viscous, the covered-claying method is less effective at separating them from the sugar and fewer white sugar crystals result. These challenges prompted producers to develop the “applied-pressure” method, in which the sugar was pressed by a weight from above. Footnote ⁵²

While the Chinese agricultural manuals did not contain any mention of an applied-pressure method per se, they included discussions of elementary versions of it with instructions to “press” or “push against.” Ikegami was already experimenting with such methods in the 1760s, presenting it to a government audience in 1766–67.Footnote ⁵³ This shows that the applied-pressure method did not replace the covered-claying method but coexisted with it for decades. While manuals imported from China offered important hints which prompted this technological change, the parallels with the process to manufacture soy sauce and sake also suggest a Japanese provenance for this technology.

Despite the import of books explaining sugar technology from China in the early eighteenth century, and despite the proliferation of sugar-making manuals from the late eighteenth century written by Japanese honzōgakusha, books are only useful to a certain extent. As Joseph Needham argues, an individual is needed to adapt the models of a technology to specific conditions on the ground, making adjustments as needed, correcting and explaining the procedures for others to learn.Footnote ⁵⁴ In this way, despite the import of written information, the true revolution in sugar making occurred over the course of the mid- to late eighteenth century when this new knowledge was digested and successfully applied in the Japanese islands.Footnote ⁵⁵

Historians such as Uemura Seiji and Sucheta Mazumdar have suggested Latin American influence on Japanese sugar technology. Uemura finds that certain features of the sugar mill in Japan, such as rectangular holes in the foundations, are similar to those used in European colonies in the Caribbean. Mazumdar adds that the dimensions and a few features of the mills appear to have more in common with Latin American technology than with Chinese.Footnote ⁵⁶ Meanwhile, illustrations of technology are similar to Chinese illustrations except that the individuals wear Japanese clothes and have Japanese hairstyles. An example also shows a holder for the sugar cane as it is fed through the rollers. Presumably, this keeps the cane at an even height as it is fed through the roller; it may also help to prevent injuries. Teeth for the rollers were a further consideration: the size and weight of the rollers affects the number of holes and pegs necessary, as does their prominence coming out from the top of the roller. The size of the rollers also affects how often the pegs make contact with the holes, and thus how quickly the pegs deteriorate. Thus a “spiral” pattern was grooved into the top of the roller, an example of a small but important innovation. The three-cylinder mill made its way to Japan via the Ryukyus, though its first mention of being used in mainland Japan was in 1756, decades after its invention in Ryukyu in 1673, but it is possible that it was used earlier on Amami.Footnote ⁵⁷ With Ryukyu open to Chinese markets and technology, and Nagasaki to the Portuguese and the Dutch, the possibility remains that sugar technology arrived through either of these routes, including from Taiwan – which in the seventeenth century had both a Spanish and Dutch presence, roughly coinciding with when the Dutch ruled part of Brazil.

While Amami sugar producers used both animal and water power as the motive force behind the cane rollers, in Sanuki oxen were the main providers of motive energy, with little evidence of waterwheels until the Meiji period (1868–1912). All of the mills were made with a wooden frame; the rollers they supported were originally made of wood, then stone, then iron, although iron rollers never became prevalent. The pots in which sugar was boiled were made of iron, but the other containers and equipment were made from wood or basic, unglazed pottery.Footnote ⁵⁸ The commercial success of Shikoku’s sugar industry despite the lack of waterwheels or iron rollers, even when this technology existed in other parts of Japan at the time, suggests that technological advantage was not the primary factor in Shikoku’s success. Adapting to local conditions, a favourable geographic position, and being attuned to the most lucrative market may have been more decisive.

The Satō seisakuki (Record of sugar making) Sugar Manual, 1797

Among the many historical documents which demonstrate a variety of sugar-producing methods in eighteenth-century Japan, one stands out for its clarity and the context in which it was written. The Satō seisakuki (Record of sugar making) was written in 1797 by a shogunate official who was sent to the Kishū region in Western Japan to learn the method from producers and experimenters there. Although a great deal of secrecy surrounded this technology, this manual was an attempt to publicise the method of producing sugar for the explicit purpose of making use of barren land and thus enriching the domains.Footnote ⁵⁹ With both text and detailed illustrations, the Satō seisakuki describes a simple claying method process for producing sugar used in Japan at the time. The text emphasises how the process could be performed with relatively basic tools one has to hand as long as one can cultivate the cane, thus encouraging entrepreneurial farmers to attempt it. It thus also stands as evidence of the shogunate’s enthusiasm for sugar production as a solution to agricultural stagnation.

After a discussion of how to plant the cane, the manual shows four types of sugar press. The first is a three-roller vertical press to be pushed by four persons, then an image of a smaller version pushed by two people while two sit on the ground feeding the cane through the presses, then a large waterwheel-powered version with six rollers, and finally a smaller waterwheel-powered version with two horizontal rollers. These show the variety of potential roller systems that can be used, at various scales. While waterwheel-powered rollers are more efficient, oxen- or human-powered versions were most common in Japan, suitable for its relatively small-scale production. The manual indeed notes that if these machines are not available, similar pressing tools used for squeezing fruit or for oil or soy sauce production can be used.Footnote ⁶⁰

Following this method, the manual assures the reader, you can produce the white sugar which is sold for a desirable price on the markets in Osaka. Although the manual intends to demystify the process, there are clearly some difficult and complex parts which require experience and skills, such as the timing of when to remove the liquid from the heat. Rather than merely relying on a manual such as this one, it is therefore likely, as Needham argues, that the technology was also diffused through knowledgeable farmers or local samurai officials with experience. Variables such as the type of “yellow soil” used or lime would also vary from place to place, meaning this manual was more of a rough guide to be refined by local knowledge. The scale of the operation, requiring a furnace, specialised tools, and manpower, also demonstrates how cultivating and refining sugar was a large project with considerable expenses, perhaps requiring a collective operation in a village or among several households rather than a lone cultivator.

The large number of experimenters, often entrepreneurial farmers or lower samurai officials, all had connections with the authorities: the domestic production of sugar cane and other crops was part of a broad nationwide effort to replace expensive imports, and in the case of sugar, this policy was a popular success: in 1818, 1834, and 1842 the shogunate had to prohibit farmers from changing their rice fields into sugar cane in order to ensure adequate rice production.

With a minimum of inputs from abroad and a scale limited to the small but growing domestic market, the eastern Shikoku region managed to achieve a high level of sugar-refining technology. This produced a sugar praised for its whiteness, and it survived initial exposure to the international marketplace once Japan opened its ports to foreign goods in the mid-nineteenth century. Compared with equivalent mills in the Americas, Japanese sugar presses could be easily dismantled and only required the strength of one ox, even if more were desirable. There was no need to import more advanced technology.Footnote ⁶¹ The main difference with the modern process of sugar refining was that the three processes of purifying, condensing/thickening, and boiling were not separate but one process that took place in the “oven room.” A further parallel with the Americas is waterwheel technology, used in both Japan and the Caribbean but only rarely in China.Footnote ⁶² The high level of technology with the vertical three-roller crusher and waterwheel shared between Japan and the Caribbean raises the question of why such an integrated system of production did not appear in China, from where Japan received other technology and sugar-production manuals. In the case of China, the answer may lie in the nature of the internal market, smallholder production, and lack of incentives for technological improvement. It is nonetheless argued by some historians that Jesuits in both China and the Americas were the link which explains the similarities between Japan and the New World at a time when Japan was relatively closed to the rest of East Asia and especially to the Western Hemisphere.Footnote ⁶³