Brewing Process

In early October, as the Suwa Basin fills with cold autumn air and the newly-harvested rice comes in, activity quickens at Masumi's two sakagura (breweries), Suwa Kura and Fujimi Kura. Let us give you a tour of the seven months from October until early spring, when we toji (master brewers) and the kurabito (brewery workers) watch over the brewing process with all the love, care, and strict discipline of parents for a beloved child.

Rice Milling

Masumi is the joint creation of our toji (master brewers) and the rice farmers.

The primary ingredient of nihonshu, or sake, is of course rice. Easy as that is to say, in fact there are many varieties of rice, and each has its own unique characteristics, so the quality of the sake varies widely depending on the type and quality of the rice used to brew it. Because of this, Masumi selects its rice according to a strict policy: 1) the rice must be of a variety specifically intended for sake brewing, 2) the source and quality of the rice must be beyond question, 3) only newly harvested whole-grain rice can be used. Nearly all of Masumi's rice is the premium Miyama Nishiki variety, produced here in Nagano, in the Ina Valley and in Kita Azumino.

The exceptionally high quality of Masumi sake comes from the excellent characteristics of the rice we select: 1) large grains, 2) low protein content, 3) ample shinpaku, which is the sponge-like core of the rice grain consisting of pure starch interlaced with voids, 4) the ease with which this type of rice dissolves during fermentation.

The more you polish, the finer the taste.

After freshly harvested rice is purchased, it is brought to our own milling plant for polishing. The purpose of polishing is to remove the outer layers of vitamins, proteins, and fats surrounding the starchy, sponge-like inner core of the rice grain. The less these extraneous outer layers remain, the more abundant the fragrance and the finer the quality of the resulting sake, so rice polishing is a critical step in the brewing process. The more the rice is polished, the more delicate it becomes, so we mill our rice ourselves to ensure the highest possible quality. We are the only sake brewery in Nagano that mills its own rice.

The polishing rate (seimai-buai) indicates how much rice remains after milling.

For example, a polishing rate (seimai-buai) of 60% means that 40% of the original weight of the brown rice has been milled away. A good rule of thumb is to remember that the lower the seimai-buai percentage, the higher the quality. Incidentally, the sake type indicated on the label is also determined by this polishing rate. To be labeled "daiginjo" (super premium), the seimai-buai must be lower than 50%. "Ginjo" (premium) can only be applied to sake with a seimai-buai of between 50% and 60%.

Milling too fast breaks the kernels and over-heats the rice, so this work must be done slowly and gently. It takes more than 50 hours to achieve a seimai-buai (milling rate) of 40%.

A key point is to carefully adjust the milling machine's program to match the specific characteristics of the rice.

Each milling machine is six meters high and mills about 1800kgs of rice at once.

One-thousand plump, well-rounded grains of Miyama Nishiki rice weighs in at over 25g. The milling machines run full-time throughout the brewing season.