How to Read a Sake Label: Junmai, Daiginjo and the Numbers That Matter

A sake label carries more usable information than a wine label, and almost none of it is intuitive if you have not been told the system. Learn six terms and two numbers and you can walk into any shop in Japan and buy well without asking anybody. That is what this is.

First, what sake is

Four ingredients: rice, water, koji mould, and yeast. No hops, no fruit, no barrels as a rule.

The technically remarkable part is how the sugar and the alcohol are produced at the same time. Rice contains starch, not sugar, so something has to convert it. In beer, malting does this first and fermentation happens afterwards, in two separate stages. In sake, koji mould converts starch to sugar while yeast is simultaneously converting that sugar to alcohol, in the same tank, continuously. This is called multiple parallel fermentation, and it is the reason sake reaches around twenty per cent alcohol — higher than any other brewed drink in the world, and achieved without distillation.

UNESCO added Japan’s traditional koji-based brewing to its Intangible Cultural Heritage list in December 2024, which is a reasonable recognition of a technique that has no close parallel anywhere else.

The six words on the label

Sake is officially classified by two variables: how much of each rice grain was polished away, and whether a small amount of distilled alcohol was added. That is the entire system.

Anything that does not qualify for one of these is futsushu, ordinary sake, and it makes up the large majority of what Japan actually drinks.

Two traps in that table.

The polishing figure — seimai-buai — is what remains, not what was removed. A daiginjo at fifty per cent has had half of every grain milled away. At thirty-five per cent, nearly two thirds is gone. The lower the number, the more work and rice went into the bottle. Polishing removes proteins and fats from the outside of the grain, which is where coarse and savoury flavours come from, leaving the clean starchy core.

And “alcohol added” does not mean cheap or adulterated. This is the single most persistent misunderstanding in English-language sake writing. A small legally capped amount of distilled alcohol added late in the process extracts aromatic compounds that would otherwise be lost in the press, and lightens the body. Many daiginjo intended to be aromatic are made this way deliberately. The bad reputation comes from a postwar practice of bulking sake out with alcohol and sugar during rice shortages — a genuinely poor product, and one that was removed from the classification system in 2006. Judging a modern honjozo by it is like judging modern wine by wartime adulteration.

Junmai means only that nothing was added. It tends toward fuller body, more rice character, more acidity, and it warms better. It is not a quality grade.

The two numbers

Nihonshu-do (Sake Meter Value). Positive numbers are drier, negative sweeter, running roughly from minus three to plus ten. It is a density measurement, so it is really telling you how much sugar was left unfermented.

Sando (acidity), usually between about 1.2 and 1.8.

Neither number works alone, and this is the useful part. Acidity makes sake taste drier and sharper regardless of what the meter value says. A sake at plus five with low acidity can taste rounder and sweeter than a sake at plus two with high acidity. If you only read the meter value you will buy wrong about half the time. Read them together: high number plus high acidity is genuinely crisp; low number plus low acidity is genuinely soft.

Words that change the drink completely

Nama / namazake — unpasteurised. Fresh, lively, sometimes faintly fizzy, and fragile: it must be kept cold and drunk soon. If you see it refrigerated in a shop, that is why. It is one of the great arguments for drinking sake in Japan rather than exporting it.

Genshu — undiluted. Most sake is cut with water to around fifteen or sixteen per cent; genshu is bottled as it came, usually seventeen to nineteen. Concentrated, and it takes ice well.

Nigori — coarsely filtered, cloudy with rice sediment. Sweeter and thicker. Shake or do not, depending on the bottle’s instruction.

Kimoto and yamahai — the two traditional starter methods, which rely on airborne lactic acid bacteria to acidify the mash rather than adding lactic acid directly. Slower, less predictable, and they produce noticeably more acidity and umami — earthier, gamier, sometimes almost cheesy. These are the sake to try if you find ordinary junmai too clean, and they are the ones that pair with strong food.

Yamada Nishiki, Gohyakumangoku, Omachi, Miyama Nishiki — sake rice varieties, which are not eating rice. The grains are larger and carry a starchy white core that koji can penetrate. Yamada Nishiki is the most prized; Omachi is an old variety with a devoted following and a distinctly heavier character.

Hot or cold, and when

Warming sake is not a way of hiding a bad bottle. It is a technique, and Japanese has separate names for each temperature band because the differences are real.

• Chilled — for ginjo and daiginjo. Their aromatic compounds are volatile and delicate, and heat destroys exactly what you paid for. Never warm a daiginjo.
• Room temperature — a fair default for junmai, and the condition in which most sake shows its actual structure.
• Warm, around forty degrees — the sweet spot for junmai, kimoto and yamahai. Warming opens up umami and softens acidity. This is where sake is most obviously a food drink.
• Hot, around fifty — good for robust honjozo in winter; too aggressive for anything delicate.

Ordering warm sake in Japan is not a downgrade. Asking for a good junmai nurukan in winter marks you as someone who knows what they are doing.

Buying, briefly

Sake does not improve in the bottle as a rule, so look for a recent bottling date rather than an old one. Keep it cold and dark. Once opened, most sake is fine for a week or two refrigerated, and nama should be drunk within days.

And note that Nihonshu is a protected geographical indication: only sake brewed in Japan from Japanese rice may use the term. Sake brewed elsewhere — and there is now good sake made in the United States, France and Norway — is sake, but it is not Nihonshu.

Related: wagyu, and reading the other Japanese grading system →