Understanding sake: junmai, ginjo, labels, serving and storage
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Learn about rice, koji and yeast, sake categories, polishing ratios, serving temperatures and storage, step by step.
In this article
What is sake? How is it different from shochu?
Sake, or nihonshu, is a fermented rice drink. Unlike shochu, it is not distilled. In Japanese, sake can also mean alcoholic drinks in general; nihonshu identifies this particular drink.
Rice, koji, yeast and water
Yeast cannot turn rice starch directly into alcohol. Koji enzymes break the starch down into sugars, which yeast then ferments. Koji and yeast have different roles.
- Rice supplies starch.
- Rice koji is steamed rice on which an enzyme-producing mould is cultivated.
- Yeast converts sugars into alcohol and carbon dioxide.
- Water is used from washing the rice to preparing the fermentation mixture.
From rice to bottle
The main stages are polishing, washing, soaking and steaming rice; preparing koji and a yeast starter; fermenting the moromi; and pressing. Starch conversion and alcoholic fermentation take place in parallel. Subsequent pasteurisation and dilution vary with the intended style.
A polishing ratio of 60% means 60% remains
Seimaibuai measures the weight of polished white rice remaining relative to the original brown rice. At 60%, 40% has been removed; at 50%, half remains. A lower number does not automatically mean a sake you will prefer.
Junmai, ginjo and daiginjo
Junmai means no added brewing alcohol. Ginjo and daiginjo refer to requirements including polishing and ginjo-style brewing. The terms can combine, as in junmai ginjo. This is an introductory table; additional requirements concern koji and sensory qualities.
| Name | Polishing and method | Brewing alcohol |
|---|---|---|
| Junmai | No polishing threshold | Not added |
| Junmai ginjo / Ginjo | 60% or less; ginjo brewing | Not added / Added |
| Junmai daiginjo / Daiginjo | 50% or less; ginjo brewing | Not added / Added |
| Honjozo | 70% or less | Added |
Nama, genshu and nigori
Namazake is unpasteurised sake. Genshu generally means sake not diluted after pressing to adjust its alcohol content. Nigori retains fine rice particles, for example through coarse filtering. These describe different features from junmai or ginjo and can appear together on one bottle.
How to read a label
Start with the type, ingredients, alcohol content and storage instructions. Nihonshudo alone does not determine how sweet or dry the sake tastes; acidity also matters.
- Type: junmai, ginjo, nama and other terms.
- Ingredients: rice, koji and any added brewing alcohol.
- Alcohol content: read the value on that bottle.
- Storage: check whether refrigeration is required.
- Producer and address: identify the brewery.
Chilled, room temperature or warm
Temperature changes how sake is perceived. The JSS English guide gives broad ranges of 8–15°C chilled, 15–25°C at room temperature and 40–50°C warmed. These are not universal recommendations for every bottle. Begin with the producer’s guidance and observe how the same sake changes with temperature.
Storage: avoid light and heat
Sake is sensitive to light and temperature. Avoid direct sunlight and heat, and follow the label. Unpasteurised sake needs particular care with refrigeration. After opening, reseal the bottle, refrigerate it and enjoy it reasonably soon. One fixed storage period cannot suit every opened sake.
The essentials
Sake is fermented, with different roles for koji and yeast. Junmai and ginjo describe separate aspects of a sake. The polishing ratio measures the rice remaining. Storage instructions are as useful as the category name.