Brewing

Rice is washed and allowed to absorb water. Soaking time can be managed to the second — a small calibration that has an outsized effect on the final flavour.

Rice is steamed in a traditional koshiki vessel. The ideal result is firm on the outside and soft inside (gaiko-nainan) — a texture that supports both koji growth and clean fermentation.

Koji mould (Aspergillus oryzae) is cultivated on steamed rice under carefully controlled temperature and humidity. The koji secretes enzymes that will convert starch into fermentable sugars — the heart of sake's flavour.

Koji, steamed rice, water, and yeast are combined to cultivate a large, healthy yeast population. Lactic acid suppresses unwanted bacteria. The method — kimoto, yamahai, or sokujo — is where a brewery's character begins to show.

Koji, steamed rice, and water are added to the starter in three stages (soe, naka, tome). Spreading additions over four days protects the yeast from dilution while steadily scaling up volume — a technique unique to sake.

Inside the tank, saccharification by koji and fermentation by yeast run simultaneously — the parallel multiple fermentation found nowhere else in the world of drink. Long, cold fermentation builds depth and complexity.

The finished moromi is pressed to separate clear sake from the lees (kasu). Pressure and timing — first free-run (arabashiri), middle-cut (nakadori), and final press (seme) — each yield a distinctly different product.

Sediment is removed, then the sake is gently heat-pasteurised (hi-ire) to stabilise quality and begin ageing. Unpasteurised namazake and undiluted genshu skip steps here, each creating distinct characteristics.