A Closer Look: Rice

While the analogy “what grapes are to wine, rice is to sake” isn’t quite true, rice is naturally still a very important element of sake production and has an influence on the character of the final product. In this article, we will talk a bit about rice farming and have a look at some of the most popular rice varieties used for sake brewing.

Farming has always been hard work. “Rice Cultivation through the Four Seasons” from a pair of six-panel folding screens (ca. 1700–1725), LACMA

From seed to sake

Rice farming is hard work, and as the rising age of Japan’s farmers shows (now well over 60), it’s not a popular job. Growing rice for sake brewing is even more difficult, because of the specific requirements with regards to grain size and composition. Rice that is to be used for sake brewing should have large grains, which takes longer to ripen than conventional table rice. This also means that the farmers have to be careful with their use of fertilisers: a boost of nutrients at the wrong time could mean that the plant puts all energy in the stalk and leaves instead of the grains. many of the older varieties are also very tall and fall over easily; especially the late-ripening varieties are in danger during typhoon season in late summer/early autumn.

The graphic below gives a rough overview over the year of a rice farmer. The exact dates depend on the climate and weather conditions as well as the variety one wants to cultivate. It’s worth mentioning that the other months are not “free time,” as many farmers will alternate the fields with another crop (wheat, soybeans…) in the other half of the year.

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The rice-growing year starts with seedling preparation in March/April and ends with harvesting and drying the rice in late September/October. (Click to enlarge)

Raising and transplanting seedlings

The seedlings are planted with the help of a specialized machine

Farmers can either save some good-quality grains from the previous season, or buy seeds from a company which are guaranteed to show the expected traits of the variety. The seeds are germinated, planted and raised to a certain length in small containers with soil.

When the seedlings are ready (at about 15cm length), they are transplanted into the field. this usually happens around late April, but can be as late as mid-June for some varieties and climates. In the cooler regions of northern Japan, seedlings need to be planted earlier than in the warm South-west. The transplanting can be done by hand, often with the help of the whole community, or —much more common and much more efficiently— by machine.

Paddies and puddles

Rice paddies are an important part of the ecosystem and home to many insects, birds and other animals. (Photo: flickr/harum.koh CC BY SA 2.0)

In Japan, rice is generally grown in irrigated paddies, which are flooded and drained multiple times in the course of a growing season. During the dry periods, the plant slows its growth and instead puts more energy in the grains.

Sometime in August, the first ears of grain appear. The precise timing again depends on the variety and the region. The grains will need until late September to ripen, when they turn golden brown.

Harvest time

When the farmer is satisfied with the quality and ripeness of the grains, they will drain the field a few days before the scheduled harvest to give the grains a last boost and also to make the field easier to work on. Unripe, green grains would give undesirable flavours, but overripe grains are very dry and crack more easily. Harvesting is usually done by machine; the stalks are cut off a few centimetres above the ground and the rice is removed from the stem..

The rice is dried until it has reached a moisture level of ca 15%. It is threshed and can then be stored for as long as necessary.

From field to fermentation tank

Usually, sake breweries don’t cultivate their own rice; in fact, it used to be illegal and only since the 1990s has there been more focus on rice-growing practices. Before, brewers had little influence on the raw material they got. The big companies purchase rice from cooperatives or distributors. But many, especially smaller ones, work closely together with contract farmers to ensure that they get grains that perfectly suit their needs with regards top quality and brewing properties. This also allows them to experiment with some more unusual or older varieties. Recently, some breweries have taken clues from the domaine concept (as is typical in the wine world) and work their own fields as well. Taka in Yamaguchi Prefecture is one such brewery.

Varieties of Brewing Rice

Of the ca. 270 rice varieties varieties cultivated in Japan, about 100 are sake-specific rice or brewing rice, explicitly made for sake brewing. (Compare this with close to 1,500 grape varieties used in winemaking worldwide and over 350 in Italy alone.) By volume, they make up just about 4% of the total production. All are varieties of Oryzae Sativa Japonica, Asian short-grain rice, which is the prevalent kind of rice in Japan.

What makes a rice variety suitable for brewing?

It is perfectly possible to make sake —even high-quality sake— with regular eating rice, but these varieties have been selected and bred for certain traits that make sake production much easier and help brewers in achieving their desired profile.

Typical composition of brewing rice (unpolished)

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The starchy core of the grain (shinpaku in Japanese) can have different shapes that affect how much the rice can be polished. (Click to enlarge)

Generally, you will want large grains that are resistant to cracking (allowing for higher polishing rates) but also have a good water absorbency. They should have a well-defined shinpaku (a “heart” of pure starch in the center of the grain) and be low in protein, which would give off-flavours.

Each variety behaves a little differently and the brewery workers have to adjust their techniques and timing accordingly. Some can be polished very highly and are perfect for producing light and fragrant daiginjo, while others are better suited for more rustic styles of sake. New varieties are constantly being developed, mostly funded by prefectural governments or the Ministry of Agriculture & Fisheries.

Grains of Yamada Nishiki rice. Unpolished brown rice; polished to 45%; and polished to 23%. The sample was kindly provided by Asahi Shuzo.

Mix and match

It is possible to mix different varieties in one sake. For example, a brewer might use one variety for making koji and another for the other steps of the process. The quality of the koji rice is especially important for the flavour and character of the sake, so it pays to give it some extra attention. However, it is worth keeping in mind that single-variety or mixed-variety does not necessarily mean better or worse quality, although most premium sakes nowadays are single-variety. In any case, the variety/varieties used have to be stated on the label, with their respective share in %.

Most-used varieties of brewing rice

Below, we will have a look at some of the most popular varieties of sake rice.

Photo: Adobe Stock

Yamada Nishiki 山田錦

Region: Hyogo
Since: 1936
Grain weight: 28g/1,000 grains

Yamada Nishiki is by far the most popular rice variety for sake brewing today and makes up a little over ⅓ of the total sake-specific rice grown in Japan with a volume of 38,853t (2015).

Yamada Nishiki has very large grains and a large, oval-shaped and clearly defined starchy core (Shinpaku). It is very well suited to high polishing, makes good-quality koji and produces a sake with depth and richness of flavor and a soft texture. It is optimal for fragrant ginjo-style sake, earning it the title ‘King of Sake Rice,’ and is a popular variety for making sake for the National Sake Competition.

While 70–80% of Yamada Nishiki is grown in Hyogo, where it has been the recommended variety since 1936, it is now cultivated in 33 prefectures from Kyushu to Miyagi and Yamagata. But Hyogo-grown rice remains the gold standard and is regarded as the best quality.

The seeds are strictly controlled to ensure consistently high quality and purity. In addition, a rating system, similar to the vineyard classifications of Burgundy or Bordeaux, has been put in place in the late 1970s (but largely based on older documents from the 1930s), that rates not only each village but each field according to the quality of rice it can produce. However, even an enthusiastic sake drinker doesn't have to worry much about these details. Only few brewers put such information on the label, and if they do, it’s usually only for their super-premium product, where declaring the use of super-premium rice gives a marketing advantage.

Yamada Nishiki is not easy to grow. The plant is comparatively tall, reaching up to 130cm, and top-heavy and therefore prone to fall over. It is also not very disease-resistant and requires the right balance of nutrients and a clay-rich soil. Yield is about 510kg/ha.

Almost every brewery in Japan uses Yamada Nishiki for at least one of their products. Asahi Shuzo alone purchases about 20% of the total production for their popular brand Dassai. With such high demand, the area where Yamada Nishiki is grown has risen constantly over the past few years and is now at over 40,000ha. Naturally, the best quality grades of this rice (i.e. Hyogo-grown Tokujō ‘Special Top Grade’) are being traded at a high price, which can reach over 200EUR for a 60kg bag (if you can get it!).

Unpolished grains of Hyogo-grown Yamada Nishiki. If you look closely, you can make out the white, starchy shinpaku at the center of the grain. Photo: Simon-sake [CC BY-SA]

Gohyakumangoku 五百万石

Region: Niigata
Since: 1957
Grain weight: 26g/1,000 grains

Gohyakumangoku means ‘five million koku’ (1 koku = 180 liters), a name it got in 1957 when Niigata’s rice production reached that volume for the first time. A longtime favourite of brewers, it got pushed to second place by Yamada Nishiki in 2009. The harvested volume in 2015 was 26,247t or 24.6% of the total production of brewing rice.

Gohyakumangoku is often selected because it is easy to make koji with. The relatively hard grains also do not break up too quickly —although they cannot take the same high polishing ratios as Yamada Nishiki— and give off little flavour into the fermentation mash (moromi), so it is perfect for the light style of sake that Niigata Prefecture is known for.

The grains are medium sized but the starchy core is relatively large, which makes it less suited to super-high polishing. The plants are smaller than Yamada Nishiki and grow about 100cm tall, making them more suitable to withstand harsh winds. Bacterial leaf blight, which causes wilted seedlings and dry leaves, can be a problem for farmers.

Older varieties tend to grow much taller. Yamada Nishiki (on the very left) also has very long stalks that can reach up to 130cm, Gohyakumangoku (fourth from the left) is much shorter. Number three from the right is Koshihikari, a popular variety of table rice, that grows shorter than most sake rice.
Photo: Takuya Oikawa [CC BY-SA], edited

Miyama Nishiki 美山錦

Region: Nagano, northern Japan
Since: 1978
Grain weight: 26g/1,000 grains

This variety was created in the late 1970s by the Agricultural Experiment Station in Nagano via mutagenesis of Takane Nishiki.

Miyama Nishiki has medium-sized grains with a good rate of shinpaku appearance. It is very low in protein and well suited for producing ginjo-style sake. Sake made from this variety is often quite smooth and soft but with a good depth of taste.

The plants are well adapted to cold climate and therefore popular in the northern prefectures like Nagano, Akita, Yamagata, Fukushima and Miyagi. Miyama Nishiki is also often used for cross-breeding to create other cold-resistant rice varieties.

Omachi 雄町

Region: Okayama
Since: n.a.
Grain weight: 27.3g/1,000 grains

Omachi is an ancient variety with almost mythical status among sake enthusiasts. It is the oldest variety still in use today and many other rice varieties have been derived from it, including the famous Yamada Nishiki and Gohyakumangoku.

It was discovered by a farmer around 1860 and was originally developed as a table rice variety, but soon became very popular for brewing, even for competition sake. At the height of its popularity, there were approx 9,000 ha planted, but production fell sharply during WWII and never recovered. In the 1970s, there were only a few hectares of Omachi left, but it could be saved from obsolescence and possibly extinction with the efforts of local breweries. By 2014, the plantings had recovered to about 500 ha.

Omachi is a difficult variety to cultivate, prone to disease and with low yield. Like many older varieties, the top-heavy plants grow very tall, around 150–160cm or more. It is late-ripening and thus at risk of damage during typhoon season. The grains are large but soft; they easily take up moisture, are prone to breaking and are not well suited to high polishing. Omachi is mostly used for high-quality Junmai sake. In the hands of a skilful brewer, it produces well-rounded sake of great depth and with an earthy umami and a certain je-ne-sais-quoi.

Dewa San-san 出羽燦々

Region: Yamagata (almost exclusively)
Since: 1994
Grain weight: 25.5g/1,000 grains

The flagship variety of Yamagata Prefecture, named for the sacred mountains of the historic Dewa Province, bred from Miyama Nishiki. Lodging and cold resistance have both been improved compared to the parent variety.

Shinpaku (starchy core) appearance rate is good, and water absorption is high. The variety has medium-large grains that are rather soft and liquify easily. Sake made from Dewa San-san can have a variety of flavours, but often has a slight green/herbal note to it.

Junmai Ginjo made from this variety as well as Yamagata Yeast and Koji can use the “Dewa33” label (33 is a play on words; the Japanese language has many homophones). Notably, Yamagata Prefecture was also one of the first regions to obtain a GI certification.

Akita Sake Komachi 秋田酒こまち

Region: Akita
Since: 2001
Grain weight: 27.2g/1,000 grains

A relatively new breed (not to be confused with the table rice ‘Akita Komachi’), which has only been adopted as a recommended variety for cultivation in Akita Prefecture since 2003. It was bred specifically to be well-adapted to the cold climate of Akita while also showing very good qualities for brewing. The efforts were successful and the variety is now used by many of the Prefecture’s breweries.

The relatively large grains are well-suited to high polishing and have a low protein content.

Each variety behaves a little differently and the brewery workers have to adjust their techniques and timing accordingly. (Photo: Adobe Stock)

Hitogokochi ほとごこち

Region: Nagano
Since: 1997
Grain weight: 26g/1,000 grains

This variety was developed in 1994 to improve on Miyama Nishiki and has a higher rate of shinpaku appearance, less protein and is more suitable to the high polishing degrees that are needed for premium ginjo- and daiginjo sake.

Ginpu 吟風

Region: Hokkaido
Since: 2000
Grain weight: 25.1g/1,000 grains

Bred to withstand the cold climate of Japan’s northernmost prefecture Hokkaido. It is well-suited for production of high-quality sake and contributes fairly pronounced rice aromas.

Hattan Nishiki 八反錦

Region: Hiroshima
Since: 1962
Grain weight: 27.6g/1,000 grains

Large grains with well-defined starchy core and a very good shinpaku appearance rate of around 95%, but unfortunately also very brittle (although some strains of this variety fare slightly better than others). This means that the variety is mostly used for sake made from less-polished grains, like Junmai, were it lends an earthy flavour and round texture.

The plants are comparatively short and disease-resistant.

Koshi Tanrei 越淡麗

Region: Niigata
Since: 2004
Grain weight: 26.1g/1,000 grains

A cross of the popular varieties Yamada Nishiki and Gohyakumangoku, that was developed as recently as 2004 with the aim of combining the best traits of both varieties. And it seems to have been a success! Koshi Tanrei has a low protein content, can withstand high polishing rates, is perfect for Koji production and dissolves well during fermentation.

Sake made from Koshi Tanrei is often quite elegant, in perfect balance somewhere between light and rich and with a mellow aroma.

Iwai 祝

This Junmai Ginjo from Kyoto brewery Tama no Hikari proudly displays the name of the rice variety, Iwai, on the front label. (Photo: Tama no Hikari)

Region: Kyoto
Since: 1933
Grain weight: 26.7g/1,000 grains

Although it doesn’t quite make it into the top-20 list of most-used varieties, Iwai is worth mentioning nonetheless, because it is quite popular in the Fushimi area of Kyoto, one of the main sake-producing regions of Japan.

It grows very tall, has a low yield and had therefore almost completely disappeared after WWII. But the grains are easy to polish and low in protein, which makes them very well suited to brewing ginjo-style sake. Iwai produces a light, crisp and usually dry sake with a distinct aroma.

The data on sake rice varieties has been compiled with the help of the excellent “酒米ハンドブック [The handbook of brewing rice]” by Akiko Soejima (Bun-ichi, Tokyo, 2017). Unfortunately, this very comprehensive book is currently only available in Japanese.