The effect of addition fo urea on sake brewing.

Abstract

It is already known that nitrogen compounds are required by many kinds of the micr oorganismsresponsible for sake brewing. We have taken urea as one of the nitrogen compoundsand studied the effect of its addition to moromi. The experiments were made on one abnormal saké moromi and two kinds of moromi with the same composition of raw materials.
The results are as follows:
1. We added 112. 5 g of urea to abnormal moromi obtained from 8.3 koku (about 1494 1) of rice. In this case we found that the sake brewing was as good as with normal moromi, though the acidity was 0.3009 as succinic acid. This moromi showed 19% alcohol and -5.0 degree by sake-meter.
2. In the case of normal moromi, we added 100 g of urea to one of the two moromi samples with the same composition obtained from 8 koku (about 1440 l) of rice. The sake yield was increased from 72.64%(control) to 78.65%
Thus we found excellent results of addition of urea on saké brewing.