It is the “king of sake rice,” there is no challenger in sight. It is the best choice for top-grade sake for a handful of reasons, and it is as expensive as it deserves to be. Indeed, it is just one variety of sake rice, of which about one hundred exist today. And it is the most grown sake rice, with about 1000 of the 1200 kura in Japan using at least some.
Yamada Nishiki was created in 1936 as a crossbreed between two other rice strains, one being Yamadaho. This was also a great sake rice, but was too tall and lanky and frustratingly difficult to grow. So the prefectural agricultural research center at that time (which has since morphed into a broader organization but still exists in spirit) crossbred it with a shorter, sturdier sake rice called Tankan Wataribune. This made the progeny that became Yamada Nishiki more manageable and better in many ways.
Without sounding too technical, Yamadanishiki is a good rice to work with for sake brewers. Yamadanishiki rice also has breadth and depth in flavours, often with ideal levels of sweetness and umami. Rice aside, other factors that like how the brewer works on the rice throughout the production process leads to differences in the end result. And the best Yamada Nishiki undoubtedly comes from Hyogo Prefecture in western Japan, within which sits the city of Kobe.