How sake is made
Sake is made in ten steps: the rice is polished, washed and steamed, fermented with koji and yeast at the same time ("multiple parallel fermentation"), then pressed, pasteurised, matured, diluted and bottled.
Sake is made from just rice, rice koji and water (some styles add a little brewer's alcohol). Unlike wine, where grape sugar ferments directly, koji turns the rice starch into sugar while yeast turns that sugar into alcohol, at the same time and in the same tank. This "multiple parallel fermentation" gives sake its depth of umami and a natural strength of around 20% before dilution.
rice starchkojisugaryeastalcohol
grape sugaryeastalcohol
That is why sake reaches about 20% before it is diluted.
1. Polishing
The outer layers of the brown rice are milled away: they hold proteins and fats that bring rough flavours. What remains is the polishing ratio (精米歩合). 60% means 40% was milled off. The lower the number, the more fragrant and light the sake tends to be.
2. Washing and soaking
The rice is washed and soaked. Water uptake is so important that some brewers time it to the second.
3. Steaming
Rice is steamed in a koshiki, never boiled, so it stays firm outside and soft inside.
4. Making koji
Koji mould spores are dusted onto steamed rice, which then grows for about two days in a warm koji room. The koji makes the enzymes that turn starch into sugar. Brewers say "first koji, second starter, third mash": koji matters most.
5. Yeast starter (shubo / moto)
Koji, steamed rice, water and yeast build a large, healthy yeast population. Traditional kimoto and yamahai starters rely on natural lactic bacteria; the common sokujo starter adds lactic acid directly.
6. The mash and three-step brewing
Koji, rice and water are added to the starter in three stages over four days (hatsuzoe, nakazoe, tomezoe) so the yeast is never overwhelmed. Day two is a rest day (odori) that lets the yeast multiply, and each addition roughly doubles the batch. The mash then ferments cold for roughly three to five weeks.
- Day 1hatsuzoe
- Day 2odori (rest)
- Day 3nakazoe
- Day 4tomezoe
7. Pressing
The mash is pressed into sake and sake lees. Methods range from hanging bags (fukuro-tsuri) and the wooden fune press to modern machines.
8. Filtering and pasteurising
Sediment is removed and the sake is heated to about 65 °C (hi-ire) to stop enzymes and microbes. This is usually done twice, before storage and before shipping. Sake that is never heated is namazake.
9. Storage and maturing
The sake rests in tanks or bottles. Sake that rests over summer and is released in autumn is hiyaoroshi.
10. Adjusting and bottling
Water is added to bring the strength to around 15–16%. Undiluted sake is genshu (about 17–20%).
Terms in this article
Also read
- How honkaku shochu is madeKoji first, then sweet potato or barley, and a single distillation.
- How awamori is madeThai rice, black koji only, one mash, and kusu that grows with age.
- Types of sakeJunmai, ginjo, honjozo, and styles like nama, genshu and nigori.
- How to read a sake labelGrade, polishing ratio, ingredients, SMV and acidity, nama and genshu, bottling date.