The introduction of the waterwheel in the 17th century, which eliminated the need for the manual polishing of rice grains, allowed Japan to begin producing saké at an industrial level for its greater population. Today Japan remains at the cutting edge of technology in its brewing practices. However, the traditional methods of handcrafted, artisanal saké remain alive in smaller and often family-owned breweries. Many of these showcase local ingredients and focus on microclimates to make what is known as ‘jizake,’ or regional saké.
Sake with the lowest milling requirement at no less than 30% milled, so that 70% of each rice grain remains, is simply called Junmai. It is made of water, koji mold, yeast and rice. The categories of saké are established not by rice variety, but by their polishing or milling percentages. Junmai is also brewed in the absence of added alcohol. Some brewers, in search of other flavors, aromas and textures, will add a small amount of distilled alcohol during the brewing process. But the alcohol in any saké labeled Junmai will come purely from fermentation.