We investigated the effect of monoglyceride addition on the digestion of steamed rice by the officialanalytical method for sake brewing. Monoglyceride (MG) is widely used as a material to prevent adhesion of steamed rice in the sake production process. We examined the degree of steamed rice digestion with changes in rice soaking time, the timing of MG addition water, and MG concentrations. The resultswere as follows: 1) MG addition did not affect the water absorption rate. 2) The steamed rice with the addition of MG was more soluble than the rice without MG provided there was a short soaking time in the MG containing water. 3) The longer the soaking time in water was, the more amino acidswere liberated from the steamed rice. 4) Thesteamed rice was most soluble when it was treated under conditions with MG at a 0.025% concentration. In conclusion, the best condition for steamed ricedigestion is the following: Soaking time should belong enough. Timing of MG addition to soakingwater should be immediately before draining the rice. The addition of the MG concentration should be 0.025% of rice weight.