How much do you know about Japanese sake?
In Japanese, the word sake is actually used to indicate any type of alcoholic beverage. The alcoholic beverage made from rice that is usually referred to by foreigners as sake is called nihonshu.
There is a wide variety of sake that is available with different tastes; this is due to the balance and different quality of ingredients. The main ingredients of Japanese sake are rice, water, and koji, a mold that is used to convert the starch into sugar. A minor change in the ingredients, like the type of rice or characteristic of water, can have a significant impact on the taste and quality of the sake.
For this reason, most of Japanese breweries are located in areas rich in pure water and quality rice to guarantee a top-quality level of sake. Different regions and individual breweries produce their own specialty sake; this results in sake with different characteristics according to the sake-process that is followed.
Types of Japanese Sake
Other than the differences between ingredients and brewing processes, there are several sake categories. The main differences lie in the percentage of rice polish, percentage of distilled alcohol added, and if it is heated or not.
Sake with higher polished rice are called “Dai Ginjo” and “Ginjo” and they use only rice grain’s core to give a clear taste. In the Dai Ginjo premium sake, more than 50% of the rice is polished away leaving a core that is less than half of the grain’s original size.
Another difference depends on the quantity of distilled alcohol that is made. For the Japanese standard, the quantity of the brewer’s alcohol added must not exceed 10% of the weight of the white rice used in making the sake. The brewer’s alcohol is a distilled alcohol of agricultural origin.
The Japanese sake (made only by rice, water, and koji) without addition of any distilled alcohol is called “Junmai” and is usually sweeter than sake alcohol added.
Sake is usually pasteurized to make it last longer but by omitting this step, we can get Namazake, a fresh-tasting sake available usually in winter, the season for sake brewing.
Sake Brewing Process
Sake is a result of a brewing process that uses rice and lots of water.
In fact, water comprises as much as 80% of the final product, so fine water and fine rice are natural prerequisites to brew great sake. In addition, great sake also depends on the technical skills applied, the type of yeast used, and the limitations entailed by local land and weather conditions.
- Rice Preparation
The first important step is rice polishing, when the protein and fat around the outer layer of the grain are removed along with its ash content and vitamin. Removing these parts is needed to prevent the flavor, color, and luster from fading and to prevent microorganisms from growing excessively. It is also important to gently polish the rice to avoid over-heating or cracking the grains. Then, the rice is washed and steamed for one hour. The steaming process is carefully controlled by using a traditional steamer.
- Koji Making
This is the most important part in the sake brewing process. Koji enzymes promote the conversion of rice starch into sugar and protein into amino acid. Koji is cultivated from spores in a humid room maintaining higher than average temperature. Over the next 36 to 45 hours, the developing koji is checked, mixed and rearranged constantly.
- Shubo (yeast)
Steamed rice, koi, yeast and water are combined and left alone for two weeks to breed sake yeast. Over the next two weeks, a concentration of yeast cells that can reach 100 million cells per teaspoon is developed.
- Moromi (mash)
As the final stage of the sake brewing process, each brewery takes great care in developing its moroni; this involves a three-times process where the shubo is mixed with steamed rice, koji, and water in a tank. The starch contained in the rice is broken down into glucose due to the workings of koji while alcohol fermentation is promoted by yeast. This takes place over four days and results in doubling the size of the batch each time. This mash ferments over a period between 18 and 45 days. Temperature and other factors are measured and adjusted to precisely create the flavor profile that is being sought.
- Heating & Packaging
When everything is right, the sake is pressed. Through one of several methods, the non-fermented solids are pressed away and the clear sake runs off.
After sitting for a few days to let more solids settle out, the sake is usually charcoal filtered to adjust its flavor and color. This is done to different degrees at different breweries, and it goes a long way in dictating the style.
Most sake is then pasteurized once. This is done by heating it quickly by passing it through a pipe immersed in hot water. This process kills off bacteria and deactivates enzymes that would likely affect flavor and color later on.
Finally, most sake is left to age for about six months to round out the flavor before shipping. Before being shipped, it is mixed with a bit of pure water to bring the near 20 percent alcohol down to 16 percent or so, and blended to ensure consistency.