The oldest surviving method of making a starter mash, invented 6 centuries ago by monks in Nara’s Shoryakuji temple. The process begins by placing uncooked rice in a tank of water. Then take a sack of cooked rice (the otai) and massage it in the water for 2-3 days. As the rice dissolves, it provides nutrients for the microorganisms. Lactic acid develops naturally and turns the water sour. The brewer then separates the rice and liquid, steams the rice, and returns it to the liquid, along with the otai rice and koji to ferment.

Sake fermented at low temperature from rice with at least 50% of its volume milled away.

Undiluted. Brewers can add water after pressing to bring the alcohol percentage down. Genshu is sake in its original form. 

Sake fermented at low temperature from rice with at least 40% of its volume milled away.

Sake made with just rice, koji-kin, water and yeast, without the distilled alcohol—usually derived from corn—that brewers can add just before a sake is pressed. Kuro Kura only offers junmai sakes. 

Dry sake.  Okarakuchi and chokarakuchi both mean extra dry.

Fortified sake. Brewers use sake instead of water in the final stage of the fermentation process. Like other fortified drinks, these tend to be big, viscous, dessert-style sippers. 

For around 400 years, before lactic acid was commercially available, this was how almost everyone made their starter mash. The brewers need lactic acid to create an environment for yeasts to proliferate. In olden days, they had to make it themselves. They did that by combining steamed rice, koji-rice and water in a small tub and mashing it vigorously, encouraging lactobacilli to enter the mix and, eventually, produce lactic acid. It is arduous work, and few brewers bother with it today, but the payoff is usually a sake with bold acidity and great character.

Aspergillus oryzae. A fungus that releases enzymes to transform rice starches into fermentable glucose, and help dissolve the rice during fermentation. Brewers inoculate freshly steamed rice with it. 

Aged sake. Historically, aged sakes were prized in much the same way aged whiskies or rums are, but taxation, fashion and war intervened and fresh sakes became the norm. A koshu revival has been, er, brewing since the 1970s and there are now superb examples from many of the breweries we work with.

The owner of the brewery.

See Bodaimoto, left.


Unfiltered. All sake must be pressed. Most sake also goes through one or two further stages of filtering—usually with charcoal powder and a filtering machine—to remove any remaining insolubles. Proponents like the extra fining for the clear sake it produces. Critics say it strips away character as well as colour. It’s the sake equivalent of the debate over fining wine or chill-filtering whisky. 

Unpasteurised. Most sake undergoes two heat treatments before shipping to kill off any yeasts or other microbes in the brew, much like adding sulfites to wine. Nama sakes are alive and evolving.  

Cloudy sake, created by adding some of the lees back into the brew after pressing. 

The head brewer.

The most technically difficult way to make a starter. As with the kimoto method, it involves using bacteria to create first a lactic acid environment and then a yeast solution. Instead of pulverizing the mix, you add warmed water to the mash — and wait. Some brewers will add yeast at this stage; others will wait for ambient yeasts to find their own way in. Either way, it requires impeccable timing and temperature control and takes twice as long as the quick-brew modern method. 

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