Perhaps the best way to buy sake is to have tasted enough to know exactly what you are looking for, and find that label. Advice and recommendations go a long way too. But we all need to foray into the unknown and try new things at times.
When choosing an unfamiliar sake, there are often several numbers listed on the label. These are supposed to be helpful, but can only confuse and obfuscate if their meaning is unknown. The nihonshu-do is one such number. Listed on many sake bottles, or maybe on a tag on the shelf, the nihonshu-do is a number that is supposed to provide an indication of how sweet or dry a sake might be. Although the era when sake was classified into either the sweet or dry camps — and nothing else — is all but over, this parameter is still often encountered.
Technically speaking, the nihonshu-do is the specific gravity of a sake, or the density of the sake relative to pure water. In the fermenting sake mash known as the moromi, koji mold breaks down starches in the steamed rice into various types of sugar molecules. Most of these (those that are glucose) will be converted by the yeast into alcohol and carbon dioxide. Others (non-glucose sugars) will remain as unfermented sugars.
The combination of heavier sugar and lighter alcohol will yield a measurable density to which a number can be affixed. This density is measured with a hydrometer — a small cylinder set to float inside a small tube of liquid. On to this, an arbitrary scale has been assigned.
Based on that arbitrarily affixed scale, a density corresponding to that of pure water is given the value or zero. For a sake with this reading, the lighter alcohol and heavier residual sugar combine to return the density to that of water.
Negative values, by ancient industry convention, indicate more residual sugar, and positive values indicate less. Most sakes today have nihonshu-do values between -3 and +10, although theoretically there is no limit. Generally speaking, the higher the nihonshu-do value, the drier the sake.
But the question of what constitutes sweet and dry is not exactly scientific. Years ago, zero was considered neutral. As the popularity of dry sake has grown wildly, the nihonshu-do of a sake generally thought of as neutral has risen to about +3 or so. A sake claiming to be dry would hover at maybe +8 to +10, while -3 would indicate a fairly sweet sake. Or so goes the theory.
If only things were that simple. Beyond the nihonshu-do are a myriad of other factors that help determine how a sake will taste. Most significant may be the acidity. A good high acidity may increase the sense of dryness of a sake by lightening and spreading out the flavor. A low acid content, on the other hand, can help a sake to feel fuller and heavier, and increase a sense of sweetness.
There are more. These include temperature of the sake, accompanying food, any immediately previously tasted sake and how the sake cup you are drinking distributes the sake across your taste buds. The hardness or softness of the water and how much the sake has been filtered are two more factors. If each of these adds a 10 percent to 20 percent variation, they can easily have a huge effect on the finally perceived flavor profile, easily eclipsing what notion might be gathered from the nihonshu-do alone.
At the end of the day, the other contributing factors are so numerous, as to render the nihonshu-do by itself fairly useless. That personal-opinion laden disclaimer aside, it is always educational to note the nihonshu-do of a sake being tasted, if only to note how it tastes compared to how it should taste.
In several English-language books on sake, the nihonshu-do is referred to as the Sake Meter Value, or SMV. Don’t get freaked if and when you come across this; it is exactly the same thing, rendered in a supposedly more easy-to-remember form. Although it is very common, but not universal, to see the nihonshu-do and acidity listed on a bottle of decent sake, this was not always the case. Many give credit to Takeshi Sato for getting the ball rolling in encouraging sake brewers to provide this information. Sato owns Taruichi, a wonderful sake pub/izakaya in Kabukicho [(03) 3208-9772] specializing in whale cuisine and rare sake, that was apparently the first place to begin listing that information on its sake menu long ago.
On the evening of Saturday, Aug. 21, Japan Times Ceramics Scene columnist and yakimono expert Rob Yellin and I will be hosting our fourth sake and Japanese pottery (sake utensils, of course) seminar at the sake pub Mushu, near Shin-Ochanomizu/Awajicho stations, 6-9 p.m. If you are interested in more details and/or attending, please e-mail me or call/fax me at the e-mail address or number below (e-mail is preferred). Participation is limited to 45, and is filling up fast.
Questions about sake? Ask by e-mail at email@example.com, or fax your name and address to (03) 3460-8263. Also, to be put on a contact list for information on sake-related tours, events and seminars, send an e-mail or fax me. For oodles of information about sake, visit www.sake-world.com
Kotsuzumi (Hyogo Prefecture)
Seimai-buai: 50 percent
Kotsuzumi presents the all-too-rare quality of being more intuitive than in-your-face with its greatness. Behind a modest and demure surface is a well-orchestrated blend of flavors and fragrances that eternally entice. There are some nice banana essences in the nose, but you have to coax them out. Smooth and light with a gentle richness hidden just below the surface. The flavor changes quite a bit with temperature, so experimenting is highly suggested.
All Kotsuzumi products are recommendable, and all maintain a gossamer thread of distinction that sings of Kotsuzumi. The label designs are unique and attractive, with gentle colors and bold, angular kanji characters, that make them easy to spot.