It is known that proper management of paddy fields contributes to the improved yield and quality of rice grains. In particular, differences in the amount and timing of fertilizer application affect the 1,000-grain weight, quality in appearance, and protein content of rice grains, all of which are important for the raw material of sake. However, the relationship between such differences in rice cultivation and the fermentation properties and taste of sake is not well understood. In this study, to obtain new insights into the relationship, we combined rice cultivation test and small-scale sake brewing test.

Fig. 1 Rice cultivation and sake fermentation tests. Rice pot cultivation under varying fertilization
conditions (left) followed by small-scale sake brewing using the rice grains (right) is conducted.

Fig. 2 Sake quality analysis. For example, amino acids and related compounds in sake are quantified
by using the amino acid analyzer (left). A chromatogram of amino acid and related compound peaks is shown (right).