Yamahai shikomi (yeast-starter method without yamaoroshi)

Yamahai shikomi (yamahai-jikomi) is one of the traditional methods of preparing the shubo (yeast starter) in sake production. The technique developed as part of kimoto brewing (the traditional yeast-starter method) and is characterized by its use of naturally occurring lactic acid bacteria, which gives the sake a rich, full-bodied flavor. The defining feature of yamahai shikomi is that it omits yamaoroshi, a step that was traditionally carried out when preparing the shubo. Yamaoroshi was heavy labor that involved grinding the rice ingredients, and experiments at the National Brewing Research Institute in 1909 (Meiji 42) showed that an equivalent shubo could be obtained without it. Following this result, many sake breweries adopted a policy of abolishing yamaoroshi, and the name yamahai (short for yamaoroshi haishi, "yamaoroshi abolished") came into being. As the saying "Don't crush with the paddle; dissolve with koji" suggests, the method places importance on the natural saccharifying enzymes of koji, and fermentation was expected to proceed more smoothly as a result. Sake made with yamahai shikomi has a distinctive, deep character and is rich in aroma and umami. The technique is still used by many sake breweries today.