Japanese scientists are champions at crossbreeding. This applies to many fruits and vegetable available from the shelves of Japanese grocery stores… as well as cereals such as rice.
There are about 260 rice varietals in Japan, out of which a hundred are specifically cultivated for sake brewing. No need to learn the exact number, it will have changed the next time you need it. The three varietals most widely used in sake brewing today (Yamada Nishiki, Gohyaku Mangoku and Miyama Nishiki) have less than a hundred years of history. The “oldest” one, Yamada Nishiki, was cross-bred in the 1920’s, the “youngest” one, Miyama Nishiki was “labeled” in the 1980’s.
Yamagata Prefecture has a history of developing new Sakamai (i.e. sake rice) strains locally. Famous for its tenderness, and the “ricy” flavours it gives to sake during the fermenation, Dewa Sansan sake rice has become an Ambassador of Yamagata Sakamai. It was cross-bred in the late 19th century by the local agricultural research institute (1885, according to the Tatenokawa brewery).
Recently Yamagata has communicated on the development of sales of brewed from “Yuki Megami” sake rice (雪女神, i.e. “snow goddess”). Yuki Megami can be “safely” polished down to low levels of Semaibuai (a delicate and expensive process) and is therefore aimed at being used for the production of Daiginjo sake. A sake graded “ Daiginjo” or “Junmai Daiginjo” is the produce of rice whose Seimaibuai (residual mass of the rice after polishing) was measured at 50% or less (of initial mass). It should be no surprise that Yamada Nishiki was a happy parent of Yuki Megami. As a matter of fact, most sake bottles competing in the annual national new sake appraisal competition are Daiginjo (or Junmai Daiginjo) brewed from Yamada Nishiki, which has therefore been collecting most trophies over the years.
A high proportion of large Shinpaku in a standard lot characterizes Yuki Megami, like its parent. The Shinpaku is this zone that looks white under the light, at the heart of the grain. The white colour is caused by the diffraction of light, and reveals a complex structure of heavy starch molecules imprisoning void.
Sake brewed from Yuki Megami is not easy to find in Tokyo yet, but I put my hand on a bottle of Kurouzaemon. This very pale yellow daiginjo brewed by Shindo Sake Brewery, located in the plain of Yonezawa, was very pleasant to drink indeed, very well balanced, and offered interesting aromas of ripe banana or quince. Its finish was clean and short.
Will Yuki Megami become the next banner of Yamagata sake? To be followed.