Japanese Sake is made from a special rice called sake rice (Saka Mai). Its unique attributes influence the flavor profile of sake.
By understanding it, you will appreciate why similar types of sake can taste different and what makes high grade sake, high grade.
1. Sake Rice is Japonica Rice
The most common rice variant produced in the world (about 80%) is Oryza sativa var. Indica or simply, ‘Indica Rice’. Sake uses a different variant called ‘Japonica Rice’. It is produced mainly in East Asia including Japan, China, and Korea.
The kernel of Indica is long while Japonica‘s is short and rounded.
Indica Rice | Photo Credit: http://dir.indiamart.com/
Japonica Rice | Photo Credit: http://thaibinhseed.com.vn/
As you will deduce from its name, Japonica rice comes from Japan and is the staple food in the Japanese diet. It is a staple for sake, as well.
2. Sake Rice is not Table Rice
To make good sake, the rice needs to have the following qualities:
- Prominent white core
- Low in fat and proteins
- Large kernel size
The officially registered designation of sake rice is ‘Shuzo-Koteki-mai’ or ‘special rice for brewing’.
2-1. Prominent White Core
Photo Credit: http://www.pref.nara.jp/
As seen in the picture above, good sake rice has a prominent white core which is not present in table rice. The difference lies is the distribution of starch.
In this white core, starch granules are loosely packed with numerous airspaces in between. The space between such molecules scatters light and makes it white.
During sake fermentation, Koji mold decomposes starch into sugar. Due to the loosely packed structure of starch in this white core, Koji is able to easily inoculate into the rice grain.
Also, this loose structure helps rice absorb water during steaming, thereby creating a good fermentation mash.
2-2. Low in Fat and Proteins
Proteins, fat, and other minerals in the rice grain create unfavorable flavors especially to highly aromatic, crisp, and light sake. The large protein molecules also prevent rice from easily fermenting, which decreases the sake quality. The protein content of sake rice is at 6-7% which is lower than table rice’s 7.4%.1-2
2-3. Large Kernel Size
Table Rice (left) and ‘Yamada Nishiki’ Sake Rice (right)
Photo Credit: http://ameblo.jp/hyogo-yamadanishiki/
The sources of off-putting flavors are found mostly in the rice bran, and less in the white core. Milling or polishing off this outer layer improves the quality of the resulting sake.
To make the highest grade Daiginjo sake, rice is polished to 50% of its original size. Moreover, some breweries polish rice up to 35%, or even 23%, of the original size to get the ideal qualities for their sake.
Since polishing makes the rice grain smaller and smaller, a larger kernel is favorable.
3. Sake Rice is Expensive
The rice plant of sake is delicate, and difficult and inefficient to grow.
The difficulty lies in its height. As you can see from the image, it goes up taller than table rice, making it fragile and susceptible to damage during heavy weather.
Photo Credit: http://www.sankei.com/
The quality of rice is determined by its environmental conditions. Providing sufficient nutrients and sunlight to the plant, while planting at lower densities are key to developing good sake rice.
As a result, sake rice is 1.5-2 times more expensive than table rice. While table rice costs 10,000-20,000 JPY, the prices of major sake rice variants range from 16,000-40,000 JPY.3-5
4. There are 3 Major Sake Rice Varieties
There are more than 100 varieties of sake rice, and each of them imparts different flavor characteristics to sake.
Among them, three varieties are widely known and used for sake making.
Photo Credit: http://www.nishiwaki-farm.com
Known as the king of sake rice, Yamada Nishiki, has a large kernel, large white core, and less protein. This makes it an ideal sake rice.
As of 2014, Yamada Nishiki is produced in 33 prefectures, including Hyogo prefecture where it originates and which account for 70% of entire production by agricultural inspection volume.6
Photo Credit: http://www.jiwamon.jp/
Together with Yamada Nishiki, this rice is commonly used in sake making. However, its too-large white core makes it unfit for high-degrees of polishing.
Gohyaku-man-goku is produced in 21 prefectures. It originated in Niigata, which accounts for majority of its production volume (50% by agricultural inspection volume).
Sake made from this variant is less fragrant than Yamada Nishiki, but is crisp and light.
Photo Credit: http://www.wakayanagi-kannari.biz/
Miyama Nishiki was developed as a mutant variety through gamma ray irradiation. Its main improved qualities are large grains, high frequency of white-core grain, and the suitability for “sake breeding”. Although not as large as Yamada Nishiki, it adequately satisfies the requirements of being considered sake rice.
Nishiki grows best in cold climates, and is, thus, produced in Northern Japan. Born in Nagano prefecture, it is now produced in 8 prefectures.
The flavor of sake produced with Miyama Nishiki is similar to that of Gohyaku-man-goku, and has a clear and light taste.
Sake rice is important in assessing the grade and taste of sake. The qualities of the rice determine how far it can be polished and what basic taste characteristics it imparts. With over 100 varieties of sake rice, you can just imagine the many different tastes sake can have. So, for your next sake selection, why not choose from the rice varieties mentioned above?
3 Ministry of Agriculture, Forestry and Fisheries