2022 Volume 117 Issue 12 Pages 855-865
“Tosaurara”, a variety of rice suitable for sake brewing grown in Kochi Prefecture, was cultivated with the goal of reducing the white core size of “Kazenaruko” and improving the cracked rice ratio. In order to confirm achievement of these goals, cultivation tests, brewing suitability tests, and brewing tests were conducted using “Tosaurara”. The yield of “Tosaurara” was 112% higher than that of “Kazenaruko” in the cultivation tests. The 1000 kernel weight was 0.9 g less than that of “Kazenaruko”, but the white core rate was about 30% lower and the white core was smaller. In the rice polished test, the cracked rice ratio of “Tosaurara” was higher than that of “Kazenaruko” in the 70% polished test, but in the 50% polished test, the cracked rice ratio was 4.2%, which was much lower than that of “Kazenaruko” at 10.6%, showing an improvement. In small-scale brewing tests, “Tosaurara” had the same sake brewing properties as “Kazenaruko”, which is highly rated for sake brewing properties, and showed a characteristic of a higher acidity in brewing tests at 50% polished rice. These results indicate that “Tosaurara” has improved white core rates and cracked rice ratios compared with “Kazenaruko”, has brewing characteristics comparable to “Kazenaruko”, and is a new variety suited to the environment in Kochi Prefecture.
