2018 Volume 87 Issue 2 Pages 147-156
We examined the agricultural characteristics and sake brewing aptitude of two Hokkaido brewers'rice varieties “Ginpuu” and “Suisei” cultivated in two regions of Hokkaido, Iwamizawa and Pippu. The brown rice yield was higher in “Ginpuu” and “Suisei” than in the table rice varieties “Yumepirika” and “Nanatuboshi” due to heavier 1000 grain weight, and was higher in “Suisei” than in “Ginpuu” due to lower sterility rate and heavier 1000 grain weight. The crude protein content of Pippu rice was lower than that of Iwamizawa rice, and that of “Suisei” was lower than that of “Ginpuu”. The selection of cultivation region and variety is important to reduce the protein content in brewers'rice. The 20-minute water absorption rate (20WR) was lower in “Suisei” than in “Ginpuu” due to lower occurrence rate of white core rice. The steamed water absorption rate of rice did not significantly vary with the region or variety. The lodging resistance and brown rice yield of the two Hokkaido brewers'rice varieties in the two regions were superior to those of “Yamadanishiki” cultivated in Hyogo prefecture, but the 1000 grain weight, crude protein content, 20WR and steamed-water absorption rate of the two Hokkaido brewers'rice varieties in the two regions were inferior to those of “Yamadanishiki”. It is necessary to improve the sake brewing aptitude rice to the same level as that of “Yamadanishiki” cultivated in Hyogo prefecture by breeding and by improving the cultivation method.
