Dassai's rice: Yamada Nishiki
At Asahi Shuzo, we only make one sake: Dassai. From all the different categories of sake, Dassai is of the most premium "Junmai-Daiginjo" category. Junmai means it is naturally fermented, without any alcohol added. Additionally the word Daiginjo is very important: it describes top-quality sake that is made using rice that has been polished to remove at least the outer 50% of the original rice grain.
Dassai is made using only one variety of rice: Yamada Nishiki rice, often called "the king of sake-making rice". In the past, we have tried to use many different varieties of rice, but Yamada Nishiki was the one we considered to be the best for us to craft a great sake. And eventually, Dassai became a Junmai Daiginjo sake only crafted with Yamada Nishiki rice.
In 2016, we were able to procure ourselves with 7,560 tons of it - which represents more than 20% of the variety's nationwide production that year. In addiction to the sheer volume of rice we acquired, we were able to secure a stable supply of Yamada Nishiki from a very special place in Japan: Fujita area of Kato city (Hyogo prefecture). This area is officially classified as "Special A area", for its suitability for cultivation of the variety. It is the highest possible ranking a rice production area can attain in tests performed by the Japan Grain Inspection Association.
Yamada Nishiki, the gold standard rice for sake making, was created in Fujita area 80 years ago at the prefecture's agricultural experiment station. One factor that makes this area suitable for growing sake rice is its climate. Often referred to as having a "Seto Inland Sea" climate, Fujita area enjoys stable weather and humidity throughout the year. There are two rainy periods - May through July (the traditional rainy season and later in September (during the fall typhoon season). The Rooko Mountains, located between the growing region and the Seto Inland Sea, block warm winds blowing from the inland sea, leaving the region cool at night. An abundance of sunshine and long periods of daylight promote photosynthesis that enables rice plants to store energy. At night, cooler temperatures slow the rate at which the plants burn energy, which advances the growth of rice grains.
In addition to climate, the area's soil is ideal for rice cultivation. The soil is said to be so rich in magnesium that even soil that has been fertilized cannot compare. Lastly, such "Special A area" must have rice fields that are arranged from east to west, a further guarantee of longer hours of sunlight. When an area offers all of these things, it is recognized as being particularly suitable for cultivating rice for sake crafting.
Fujita area is one of these "Special A area" and we have managed to contract with farmers there to purchase their entire production of Yamada Nishiki. But Yamada Nishiki is the one of the most challenging varieties of rice to cultivate. It falls easily as it is about 120cm high, 20cm taller than ordinary varieties of rice grown for eating. Its grains are also bigger: if ordinary rice weighs 22 grams per 1,000 grains, Yamada Nishiki weighs 27 grams or more. As it is taller and heavier than others, it tends to fall easily. To prevent it from falling, farmers try all kinds of things every year such as tilling as deeply as possible during the winter.