Sake (sah-kay) is the japanese word for the alcoholic liquid leftover from rice that has been polished to remove its bran, steamed, mixed with moldy rice, yeast-fermented in water and strained out of that liquid. The basic process is to start with dry whole-grain rice, remove the bran, steam the rice, let mold convert starch to sugar, add water, add yeast to convert sugar to alcohol, separate rice from the liquid, then drink the remaining liquid. The result of this process is sake, a beverage also called “rice wine”.
How much alcohol is in it?
Undiluted, the liquid resulting from the basic process is about 20%. On the shelf, it’s usually diluted with water to about 15%.
What is rice?
Rice is the seed of a specific species of grass. That seed consists of three parts: endosperm, germ, and bran. The parts used for sake consist mainly of carbohydrate.
What kind of rice is typically used for sake?
Yamadanishiki, omachi, gohyakumangoku, miyama nishiki are most popular for special-designation sake, but there are about 80-100 registered sake varietals according to wikipedia and other websites. The list changes each year as strains are added/removed. Sake rice varieties are different from edible rice in that they have less fat and protein content. At least one site claims no law requires the use of “sake” rice, though most special designation sake is made from the special rice. The rest, futsu-shu, is made from table rice due to costs and availability of sake rice. Table rice for eating usually is milled to about 90%.
What’s the difference between cheap and expensive sake?
Futsu-shu is table sake, like table wine. Tokutei meisho-shu is the special designation sake (ginjo, daiginjo, honjozo).
What is the polishing process?
It’s milling, so using a grinding stone which spins and rubs against the rice to rub off the bran.
What is bran?
Bran is the outermost layer of protein and fat that surrounds rice.
What determines the sake flavor?
An important concept related to sake and rice is that the choice of rice does not affect the final flavor and nature of the sake in quite the same way that the choice of grape might affect the nature and flavors of a wine. Yes, the choice of rice is very important. And yes, different rice varieties do lead to flavor profiles that can be associated with them – in general. But two toji (master brewers) can take the same rice, milled to the same degree, and make totally different sake in every way.
How? By creating the koji differently, or through the choice of yeast, or fermentation temperature or time in the tank. There are dozens of options at every step of the brewing process, and those choices hugely affect the nature of the sake. More so than the choice of rice? Perhaps; perhaps not. It depends on who you ask. http://sake-world.com/sake-rice-reality/
Where does the alcohol come from?
In this case, Aspergillus Oryzae mold breaks down rice starch into component sugars. Certain strains of yeast turn glucose into alcohol. The most common strains of yeast are #7, #9, and #10, as labelled by the Central Brewers Union.
Yeast isn’t everything; temperature of fermentation is essential in shaping the finished product. But as a general guideline, if you tend to prefer fruitier, more wine-like sake, you should look for sakes brewed using expressive yeasts such as #9 and #1801.
If you’re looking for subtler, more earthy rice aromas, sakes brewed with yeasts like #7 are a better way to go.
Other important terms to learn more:
– Moromi
-Shubo
-Koji