Dance of the fireflies and giant dragonflies

Looking out the window on the JR Koumi Line you’ll see small rice fields surrounding Hozumi Tenjin shrine, including those where Kurosawa Sake Brewery employees currently grow sake rice. The fields were left fallow for a long time before being handed over to the brewery about 10 years ago, so the first thing they did was start maintaining them to give them a new lease of life. Turning abandoned land into rice fields was no easy task. In particular, the brewery went to great lengths to improve the soil so it could hold more water, and even after a decade it is still work in progress.
The brewery staff working in the fields also noticed insect life near their water source – fireflies drifting by on summer nights, and giant dragonflies sunning themselves in the fall. So they decided to keep agrochemicals and artificial fertilizers to an absolute minimum in the new rice fields. Fireflies are known to live only in areas with very clean water, and the same applies for the nymphs of giant dragonflies. This larval stage can live in streams and springs for up to five years, so their presence near the rice fields proves how pure the water is. In 2023 the brewery finally switched over to farming without agrochemicals. They also use no artificial fertilizers or herbicides, and disinfect seeds only with hot water. Most people don't even know that seeds are disinfected, but if they carry disease-causing bacteria those microbes can reproduce when the rice germinates, which often results in the rice plants succumbing to disease. So rice in Japan is usually treated with a seed disinfectant. Hot water disinfection involves soaking the seeds in 60°C water for 10 minutes, reducing the risk of disease without using agrochemicals and promoting growth.

Not using agrochemicals has its disadvantages. There are a lot more weeds in the fields and most of the summer is taken up with keeping them under control, especially Japanese millet, the bane of Japanese rice farmers. It looks almost identical to rice, especially to the untrained eye. But if left to grow in the rice field it will eventually compete with the rice plants and harm their growth, leading to a smaller harvest. Keeping the millet under control is a never-ending struggle for the brewery employees, who tell the story of how there was so much of it the previous year it brought the rice plants down with it when it fell. Anyone who grows rice will have had this happen, but it underscores just how difficult it can be to raise crops. Determined not to resort to agrochemicals, the team are looking into other ways of handling the millet, such dealing with it earlier in the growing season.

Nagano native Sankei Nishiki

Yamada Nishiki is the number one sake rice in Japan, and Nagano Prefecture's Agricultural Experiment Station has been trying to develop a variety to rival it since 2003. They finally hit upon a cross codenamed Shinko 545 in 2011, which was grown and ready for test brewing in 2014. Kurosawa Sake Brewery were already growing test batches of the variety before it was given an official name thanks to their Yachiyo Bijokai – a group of about 80 Kurosawa Sake Brewery supporters who enjoy interacting with the brewery all year round, from transplanting seedlings in the Sakuho fields to harvesting, followed by experiencing the brewing process with the rice they helped to grow. The brewery's success in maintaining its rice fields is thanks to this group and the farming experience the members have built up.
After an open call for names in 2017, the Shinko 545 was renamed Sankei Nishiki, and it is this variety that is now grown without agrochemicals in the brewery's fields around Hozumi Tenjin. The name evokes the many mountains that grace the skyline of the Shinshu region, and the rice grows well in fields fed with the pure water that runs from the peaks.

The brewery staff who care for the rice fields are also the people who make the sake. They are keenly aware from polishing the rice that goes into the brewing process that making sake starts really starts before that point, namely with growing the rice. Choosing to polish rice in-house also means accepting the risk of pests attracted to the grain and increased equipment maintenance costs. But in return, the brewery can be exacting about the condition of the rice and have greater control of the entire brewing process, including preserving the moisture content of the rice after polishing.
Polishing also takes a long time: to reach the 50% minimum for a daiginjo, the rice is passed through the polishing machine about 300 times as its outer surface is gradually ground away over a period of 24-42 hours. One employee points out that as soon as the rice is harvested in September, they switch over straight away to polishing for the upcoming brewing season. And as soon as the tanks are pressed in the spring, they go straight to the fields to get ready to grow the next crop of rice. The cycle never ends, so it’s no exaggeration to say they are focused on rice all year round. The brewery staff can see the size of the grains they grew and the extent of the white starch core after polishing, which makes the careful growing and processing of their vital raw ingredient all the more dear to their hearts.

Kimoto Kurosawa junmai ginjo

made with brewery-grown Sankei Nishiki

Founded in 1858, Kurosawa Sake Brewery has a long history. When it diversified in 1898, the founder divided the businesses up between his 5 sons. The eldest operated the bank, the next son the clothing business. The third took over the brewery, the fourth went into making miso and soy sauce, and the youngest was in charge of medical wholesaling. Takao Kurosawa is the 6th generation to run the sake brewery. Many of the original buildings are still intact, and walking around the historic grounds makes you feel like you’ve gone back in time. In particular, the sake museum created when the brewery was renovated is full of objects from its past including a diorama showing how sake is made, and gems of wisdom and inspiration from the past. And right behind the brewery are the fields where Sankei Nishiki is grown without agrochemicals, fed by the same water Kurosawa use for brewing.

You might think that being made from the same water would make the rice perfect for sake brewing, but Takao notes that Sankei Nishiki actually doesn’t perform very well in kimoto, the starter method used for most Kurosawa sake. Kimoto brewing relies on microorganisms naturally present in the brewery, so the type of rice used strongly determines the nature of the finished product, which crosses over into the domain of younger brother and master brewer Yohei. Kimoto Kurosawa junmai ginjo brewery-grown Sankei Nishiki has the lactic aroma characteristic of kimoto sake, combining citrus fruit freshness with grain notes, all drawn together by a touch of bitterness and alcoholic sharpness to create a punchy and bold flavor profile. It feels young and slightly rough even when aged for 2 years, hinting at the potential for further aging to develop its flavors even more. Join Kurosawa Sake Brewery on the enchanting path into the mountains and rice fields, on their journey to discover where the combination of Sankei Nishiki and kimoto brewing will lead.

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