Sake-brewing by the Ampuled Pure Yeast Method using Culture Liquid of Rhizopus sp. in Place of Lactic Acid

Abstract

A test brewing was made by the ampuled pure yeast method, in which culture liquid of Rhizopus sp. was used instead of lactic acid in preparing moto (yeast starter). When culture liquid made by culturing Rhizopus javanicus TUA 055, or R. tonkinensis TUA 192 at 30°C for 3 days under aeration was added to the mizu-koji (mixture of koji and water), the growth of putrefactive bacteria, Lactobacillus casei B 83, was completely inhibited. A mizukoji made from rice koji 0.1kg, culture liquid of Rhizopus sp. or lactic acid solution (acidity 20.5 ml) 0.1l, and water 0.8l was applied as the soe (first addition) with ampuled pure yeast in test brewing with total rice 5 kg. General components of sake made by adding culture liquid of Rhizopus were not different from those of sake made by lactic acid solution. As to the organic acid composition, lactic acid content was lower, and malic and succinic acid contents were higher in sake with the addition of culture liquid of R. javanicus than others, though the difference did not give any appreciable influence on the taste of sake.