The rice polishing technique was rapidly developed such as an appearance of a vertical-type rice-milling machine in 1930, and the high ratio in rice polishing which was necessary for brewing ginjoshu became possible easily.
昭和5年（1930年）には縦型精米機の登場などによって精米技術が飛躍的に発達し、吟醸酒を造るのに欠かせない高い精米歩合が容易に実現されるようになった。