Sake Times reports on an Okayama brewer who is challenging the preconception that "superior grade rice is good rice" when it comes to brewing sake

The rice used for making sake, special varietals known as sakamai or sake-specific rice (酒米), is mostly grown independently by farmers and sold across Japan by groups like the Japan Agriculture cooperative. Some breweries are moving towards direct contracts with individual farmers, often in the same prefecture or local area, which gives them greater control over the cultivation process and lets them influence their raw material at an earlier stage than possible if they buy sakamai on the open market.

One pioneer of the grow-your-own model is the Okayama-based Marumoto brewery. Founded in 1967, it's one of the few to grow all of the rice it uses. Although there has been an increasing trend in recent years for breweries to grow their own rice, Marumoto has been doing it since 1986. 

They make full use of Okayama's rice-friendly climate and soil, growing only the legendary sake-specific varietal Yamada Nishiki. They also constantly research optimum rice-growing techniques in order to make the best sake, and gave a presentation on their approach at a briefing session in September 2017 where brewery representative Marumoto Jin'ichirō went into detail about how and why they grow their own rice. He emphasised that sake is made with polished rice, and that rice is polished to remove undesirable flavours - the outer layer of the rice grain contains protein, which leads to zatsumi, or off-flavours, in the brewed sake.

The current rice grading system is based on the size of the rice grain, which makes sense if you assume that the larger size grains will have a larger protein-free core when they have been milled. Marumoto disagreed. He pointed out that you need fertiliser to produce large grains, more fertiliser produces larger grains and therefore a higher grade, and that as higher grade rice sells for a higher price farmers have an incentive to use more fertiliser.

However, he claims that protein components from the fertiliser build up inside the rice grain, belying the assumption that high-grade rice under the current grading system is always "good" for making sake. Most people are unaware that these large grains could contain protein, and therefore lead to off-flavours in the final product.

The Marumoto brewery also decides at harvest time which rice is best for inoculation with kōji (kōji-mai, 麹米) or for steaming and adding to the fermentation (kake-mai, 掛米). The former should have more of the prized white shinpaku (心拍) starch core, while the latter should be low in protein. To determine which rice is best for which use, they analyse the soil composition of each of their rice fields and that data determines how much fertiliser is used, a level of attention to detail that the average farmer will simply not have.

Links

  • Original article (Japanese, Sake Times, 12 November 2017)
  • Marumoto Brewery (Japanese) Beware the early 2000s site design.
  • Japan Agriculture (JA) (English), a network of agricultural cooperatives across the country. (Also providers of one of the only banks where I lived first time I was in Japan, and purveyors of great farmer's markets.)