Why a staple crop failed to take root in ancient Japanese kitchens

New research into ancient Japanese rice farming suggests that significant technological development does not always mean the abandonment of cultural practices, particularly culinary traditions.

Archaeological evidence largely shows that the arrival of farming in various cultures around the world transformed society, but new evidence from cooking pot residue in prehistoric Japan shows that culinary traditions were largely unaffected, despite the uptake of farmed produce.

The researchers highlight that this perspective from history shows us that not all technological developments progress society at the same rate, and some cultural practices hold steady, in some cases, for centuries.

The work is published in the journal Proceedings of the National Academy of Sciences.

The arrival of rice farming, imported from the Korean Peninsula, marked a turning point for agricultural farming in Japan approximately 3,000 years ago. But while rice would eventually transform society, new evidence shows that its sister crop—millet—was largely left behind despite its popularity in Korean cooking.

Archaeologists from the University of York, in collaboration with the University of Cambridge, and the Nara National Research Institute for Cultural Properties in Japan, studied residues found in ancient pottery and charred plant remains from this period and found that although both rice and millet were introduced to Japan together, likely carried across the sea by groups from southern Korea, they did not necessarily transform society.

Dr. Jasmine Lundy, from the University of York’s Department of Archaeology, said, “Organic residue analysis has been crucial to our investigation into the earliest impacts of rice and millet agriculture. It allows us to capture how these crops were actually used, offering a direct window into the culinary practices and crop interactions of early Japanese society.”

Seed impressions on Final Jomon and Yayoi pottery confirm that both crops were present in early farming settlements in Northern Kyushu, but while millet was a dietary staple in Korea, especially during the Bronze Age, it barely shows up in early Japanese diets.

Professor Oliver Craig, from the University of York’s Department of Archaeology, said, “The absence of millet from Japanese food residues and human bones was a surprise to us, given that we knew both rice and millet had been introduced at this time.

“We know from isotope analysis of fats and oils in cooking pots that millet was a major part of the Korean diet, and continues to be eaten to this day, but it seemed that it made no impact on early Japanese cuisine.

“Environmental factors could be ruled out because we know that millet grows just as well in Japan as it does in Korea, so there was something else going on that provided a barrier to this crop being adopted in Japanese cooking.”

The team found that fish dishes, which were already a well-established culinary tradition in the country, continued to be the main source of food, despite the arrival of two important food crops.

Dr. Shinya Shoda, from the Nara National Research Institute for Cultural Properties and honorary researcher at the University of York, said, “There is evidence of Korean-style pottery and farming tools in Japan, but this didn’t line up with changes to the way people cooked and ate. Yayoi pots were still used to cook fish and other wild foods, and few show signs of being dedicated to rice-cooking.”

While the findings may have been unexpected, given the uptake of farming in Japan’s closest neighbors, there are other examples where technological development has not caused rapid change. In Southern Scandinavia, for example, hunting, fishing and gathering for wild foods continued for many years after the introduction of farming, but elsewhere in Britain, there was a quick abandonment of foraging for food in favor of agriculture.

Professor Craig added, “While we see changes in pottery styles and other forms of material culture in Japan with the arrival of rice and millet, food culture remains remarkably consistent. And while Japan’s culinary history eventually catches up with the ‘rice boom’ that we see in Korea, it may have taken some time to have impacted everyday practices, suggesting food culture is deeply embedded and can survive major technological shifts.”

The research forms part of the ENCOUNTER Project, led by Dr. Enrico Crema, at the University of Cambridge. He said, “These latest findings add to our body of work in the ENCOUNTER project, which has so far shown the diffusion rates of farming within the Japanese archipelago, the demographic impact of farming, and how different cultural traits might have been conditioned by marriage practices.”