19th-Century Kura, 21st-Century Innovation
On a fine winter morning we caught a train to Oyama City, Tochigi Prefecture. A meandering city bus took us from the train station to our destination, Nishibori Shuzo, and to our appointment with Tetsuya Nishibori, the Sixth Generation Kuramoto (brewery owner).
Mr. Nishibori is one of the most passionate Kuramoto we have ever met and certainly the most innovative. He kindly made time in his busy schedule to explain in great detail what he is doing and why. What follows is a summary of what we learned from his very informative talk and tasting notes on the sakes that we sampled on that day.
We became interested in Nishibori Shuzo due to an article that was published in Sake Industry News about their use of blue and red LEDs (light-emitting diodes) in the brewing process. Mr. Nishibori designed and patented the first clear tank for brewing sake. As no sake-tank manufacturer had experience making transparent tanks, those he approached about doing so were reluctant to take on the task. He persevered, however, and was able to convince a fish-tank manufacturer that supplied aquariums to accept the challenge, but only if it was designed by the sake brewer himself. Through this innovation he was able to see the fermentation process of the moromi (sake mash) better and adjust the frequency of stirring accordingly, rather than relying on the traditional practice of twice-daily stirring. At this point he started to experiment with LEDs, taking inspiration from indoor farming, where the effects of LEDs on yields and nutritional value (of lettuce) had already been established.
The hypothesis in a nutshell is that blue LEDs, which have a shorter wavelength, will result in a slower fermentation, yielding a sweeter sake, while red LEDs, which have a longer wavelength, will be more conducive to yeast vigor, the effect of which will be to speed up the fermentation process, resulting in a drier sake. Temperature remains a factor in this as well, of course, and the LED treatments are used in conjunction with it.
All of the samples we tasted were noteworthy. However, we will focus on five. Sake #2, Mongaifushutsu Junmaiginjo Muroka Namagenshu (門外不出 純米吟醸 無濾過 生原酒) (the second bottle from the left) has wonderful vanilla notes, a good balance between sweetness and acidity, a silky mouthfeel–always a hit with us–and comes in at 17% abv.
Sake #4 labeled “Clear Brew” is from the Mongaifushutsu series but brewed in the clear tank. Compared with the Illumina series, this sake is brewed sans LED treatment. It has some vanilla on the nose, more sweetness than acidity, and comes in at 16% abv. Sakes # 5 and 6 are in the Illumina series. The bottle to the right of Clear View is Illumina blue, which we found to have some vanilla notes and to be noticeably sweeter than Clear or Illumina red. The alcohol was 16%. Finally, Illumina red, the sixth bottle from the left, exhibited some banana and/or plantain notes on the nose, was quite dry on the palate, and contained slightly more alcohol but also labeled as 16% abv. All the nihonshu in the Illumina series are genshu, which means no water is added after brewing, and both Mongaifushutsu and the Illumina series are made from Tochigi rice.
The bottle on the far right contains a nihonshu made from green and red rice. I MY ME (愛米魅)is pale yellow, with some notes that one would expect from a sake that has been aged. The acidity is pronounced; some might even say startling. The abv is 15%, and the seimai-buai is 88%.
Nishibori Shuzo is a brewery to watch!