The Evolution of Sake: Beyond the 15% Tradition

Sake can be bottled at 13% ABV and still be genshu. ARAMASA COSMOS and KAGURA Clear offer two concrete examples. Both have a lower alcohol content than the usual 15–16% range for sake, while being finished without dilution after production.

These bottles show why lower-alcohol sake is easier to understand when we look at how its strength was achieved. Reading the genshu designation separately from the stated ABV reveals more of the decisions behind the finished wine.

Genshu Describes Dilution After Production

Genshu generally means sake finished without adding water after production to adjust its alcohol content. In a common approach to sake making, water is added to higher-strength fermented sake before bottling or at another finishing stage. This adjustment is called warimizu.

Lower-alcohol genshu calls for brewing and fermentation to be planned around the intended strength and flavour. Enzymes produced by koji break rice starch into sugars, which yeast converts into alcohol. Both processes proceed in the same moromi, or fermentation mash. Ingredient proportions, water quantity, yeast and temperature management all influence the result.

Water used in brewing serves a different role from water used to adjust finished sake. Water added to the mash with rice and koji is an essential brewing ingredient. The genshu designation concerns dilution after production, a separate stage from adding brewing water.

ARAMASA COSMOS｜Genshu Finished at 13% ABV

ARAMASA COSMOS, included in Bacchus Global’s range, provides an example of lower-alcohol genshu. The brewery’s specifications for the 2025 vintage state 13% ABV. It is made with Akita-grown Kairyo Shinko rice, using kimoto and cedar-vat brewing.

Kimoto is a traditional method of preparing a fermentation starter in which lactic acid bacteria help establish conditions for yeast growth. This starter builds the yeast population needed for the main mash. In COSMOS, this brewing method and an undiluted finish at 13% ABV form distinct parts of the same product.

COSMOS also belongs to the pasteurised Colors series. Genshu describes the treatment of dilution after production; namazake describes the absence of pasteurisation. Keeping the terms separate allows alcohol content, dilution and heat treatment to be explained individually. ARAMASA specifications vary by product and vintage, so figures should be read alongside the label on the particular bottle.

KAGURA Clear｜Yeast and Four-Stage Brewing

KAGURA Junmai Clear Non-filter Nama-Genshu, made by Matsui Shuzo in Kyoto, is also undiluted sake at 13% ABV. Kyoto-grown Iwai rice and the Kyoto yeast Kyo no Koi are used to produce this unpasteurised bottling without dilution.

Its production combines low-temperature fermentation suited to the yeast with four-stage brewing. This adds a further preparation stage to the usual three-stage approach. The brewery describes rice sweetness as a feature of the sake. The method considers lower alcohol content and the retention of rice-derived flavour together.

Clear also grew out of joint work between the brewery and a public research institute in Kyoto on lower-alcohol genshu. Although it shares a 13% ABV with COSMOS, its rice, yeast and brewing approach differ. This KAGURA nama-genshu receives no pasteurisation, and the brewery’s refrigeration instructions are another part of its product information.

Beyond ABV: Reading the Brewing Stages

Lower alcohol content first describes the proportion of alcohol. Sweetness, acidity, umami and aromatic intensity are qualities to assess separately in each sake. The shared figure of 13% provides a starting point for considering the different profiles of COSMOS and Clear.

For dining establishments in Bangkok, explaining a “13% genshu” becomes clearer when rice, yeast, brewing method and heat treatment are also identified. Both finishing through dilution and brewing to a lower undiluted strength serve particular production aims.

The evolution of sake can be understood through its widening range of strengths and the work of building flavour at those strengths. ARAMASA and KAGURA make lower-alcohol genshu tangible through their ingredients and fermentation choices.