A modern Japanese supermarket is a sad place for a cheese-lover. Beside the Hokkaido butter and yogurt sit packs of mostly flavorless cheese blocks. It is inoffensive. I associate this sort of cheese with Britain or factory cheeses of the United States. It is meant to be grated over potatoes or pasta and baked, or a slice tucked into a sandwich and promptly forgotten.
This cheese in the modern Japanese supermarket has its own unique story which comes from the development of Japan’s dairy industry in the late nineteenth century. This dairy industry arose from a desire for Japan to appear more modern, more Western, more alike to the empire-building and colonizing powers. It was also during this time that the Japanese took up bread-baking, whiskey-brewing, and the raising of cattle.
What most people do not know is that cheese culture came to Japan in two separate phases; we are living in the second phase. The first phase came in the 500s. And it was not from Western influence, but Chinese and Continental influence that people living in the Japanese islands came to make a mysterious cheese.
Immigration of people from the Korean peninsula made a big impact on the Japanese islands in the sixth and seventh centuries. When we teach this period, we often discuss how elites of the Korean peninsula married into the Japanese Yamato clans, or perhaps how Buddhist priests from the Continent brought new Buddhist iconography and teachings. But more ordinary people came to the archipelago during this time too, and with them they brought pottery and metalworking knowhow, agricultural techniques, and expertise in raising horses and cattle.
Like in the nineteenth century, when Japan emulated European cultures to appear more sophisticated, so did elites of Yamato. The Yamato court wanted to be fashionable. So the rulers set up royal ranches that specialized in raising horses, cows, and oxen to imitate the powerful rulers of the Tang Dynasty in China.
There was a demand for oxen, but truthfully, ancient Japan was not a good place for raising most kinds of livestock. Farmers had very limited amounts of land that they could use for growing their most important subsistence grains. Mountains dominate the landscape, so what little grazing land there was would be better used for growing food for people. This was the case for most of Japanese history and is the reason there was not a prominent pork or beef-eating food culture.
By the way, cows are used for milk, and oxen are castrated bulls typically used for labor, whether it be pulling a cart or a plow in the field. Oxen were used in royal fields, and in the early cities, elites used them to pull their carts around like carriages. Cows produced milk, and fashionable elites with knowledge of Chinese culture knew that this could be a special food product that only they could enjoy.
There is no record of ancient elites drinking milk in this period, but the royal ranches took the milk and boiled it down to produce a product called so 蘇. The Engi Protocols of the tenth century has the earliest description for making so, describing it as boiling milk down until you have one-tenth the original volume. The so was packed into jars, which ranchers then shipped to the palace.
This glimpse into ancient cheese-making has fascinated—and puzzled—scholars. If you simply boil milk down and then leave it at room temperature, it will go rancid. At the same time, the Engi Protocols make no mention of culturing the milk, like you would do with yogurt or cheese. Introducing beneficial bacteria, molds, or yeasts, is what gives cultured butters, yogurts, or cheeses their complex flavors and helps with their preservation. It’s one of the reasons that these foods appear in food cultures connected with pastoral or goat, sheep, or cattle-raising societies.
Japanese cooks who worked in sake or miso-making were familiar with kōji mold, or the fungus Aspergillus oryzae. But we have no such mention of a mold being involved in the making of this mysterious ancient Japanese cheese. And to be fair, the aristocratic record-keepers who wrote the Engi Protocols barely even knew about kōji mold. Ancient understanding of kōji mold was described in ways more akin to working with a temperamental ghost than a living organism. Perhaps anyone who has struggled with keeping a sourdough starter can relate to the idea that you’re dealing with a fussy spirit living in your kitchen. This is all to say that it’s not impossible that so was cultured somehow, but we have no extant record that describes culturing the so.
(The phrase ‘culturing the so’ evokes the image of teaching the cheese how to bow properly or write elegant poetry.)
Out in the ranches, government agents designated “milk households” 乳戸, who would pay their taxes by sending so to the court in Nara. These men and women were responsible for the cooking and packaging of this delicacy, which because of the unusual practice of raising cattle was consumed only at elite tables in the capital.
So was not just a milk product, but a food that could only be made at volume by the royal ranches. It developed a special cache. When an aristocrat was promoted to minister, the palace kitchens sent so to his residence for the special party he hosted. Within the palace, it was an abstinence food that was eaten with ginger, or if you wanted to benefit from its perceived healthy properties, you would eat it with wild honey.
When the government-owned royal ranches ended, so did the preparation of so, and it became a mysterious food in the historical record. Ministers no longer could eat it at banquets. Royals no longer dabbed morsels of it with honey. As the food system that allowed for its creation ended with the rise of samurai governments, so did this fussy and foreign food. The cultural cachet of the Continent and the food system that supported so had come to an end, and with it, this particular cheese.
I have seen so often misunderstood in English-language food scholarship over the years. Some people have described it as butter, which it was not, or the same as daigo, another premodern milk product, which it was not.1
Recent Japanese scholarship and recreation studies have helped us better understand this mysterious food. People in the milk households must have cooked the milk at a low heat for an extended period of time. By heating the milk around eighty degrees celsius, they would have killed off microorganisms in the milk and allowed proteins to coagulate. They put the cooked milk into jars.
Technically speaking, so is not cheese. Cheese purists would wave their fondue forks and insist that cheese is only made from curds, which are the coagulated white pieces that form when separated from the liquid whey. With so, much of the liquid is cooked away and coagulation is occurring because of the low temperature. That said, I still call it so cheese when speaking with students and nonspecialists. “So Dairy Product” does not have quite the same ring to it.
So what? Now you know what so is. Happy Monday.
1 Some of the confusion comes from erroneous later, medieval texts that confuse lost foods. Additionally, there is the question as to whether so is one of the milk products mentioned in the Nirvana Sutra, which lists five milk products and corresponding states of the growth of one’s spirit. Basically, through good practice we can turn into more delicious versions of ourselves.
More difficulty in understanding ancient milk product terminology comes from the fact that parts of the Nirvana Sutra were translated from Sanskrit to Classical Chinese, and the Classical Chinese author-translators had to create new words to refer to things from a different food culture.
乳變為酪、酪為生酥、生酥為熟酥、熟酥為醍醐、醍醐為第一
Given that these words are meant to be phases in cooking, we might understand these different milk products as milk-cream 乳 separated into buttermilk 酪 and butter 生酥, then cooked so as to yield ghee (or clarified butter) 熟酥, and then the final stage of milk in the sutra is something called sarpir-maṇḍa सर्पिर्मण्ड. In Classical Chinese this is written as 醍醐, or daigo. This last stage was thought to be incredibly delicious. However, this food is not thought to have ever existed in Japan. We might be better served by thinking of daigo as an idea rather than an actual food item.