Sommelier Talk: Episode 11 – Minerality

According to Wikipedia, minerality is “a sense of mineral-ness in the wine. It’s not an everyday word, but it’s one we use to describe wine. For sake brewing, the quality of water used is as important as the quality of sakamai, or sake rice. Each brewery opts for quality water sources, to reflect the water’s underlying characteristics. In this episode, let me explain the types of minerals contained in jozo-yosui or brewing water, and how they affect the quality of sake.

Pertaining to mineral compounds in Jozo-yosui, there are two conditions that optimize sake production. First, that jozo-yosui is abundant in potassium, magnesium and phosphorus to help vigorous yeast propagation and koji development. Second, that jozo-yosui contains calcium and chlorine which aid koji in producing necessary enzymes. All these minerals indirectly promote the fermentation of sake.

Needless to say, rice, the other major ingredient in sake brewing, contains many more minerals than water, even after polishing. However, the minerals contained in rice are bonded with proteins that must first be isolated by enzymes, thus enabling them to become nutrients for yeast and koji. On the other hand, minerals contained in jozo-yosui are free to be used right away, and therefore play a very important role in the sake brewing.

Miyamizu of the Nada region in Hyogo Prefecture and Gokosui of the Fushimi area in Kyoto Prefecture, are the two notable water sources most often regarded as the best jozo-yosui. Unsurprisingly, there are many sake breweries clustered around these two water sources. Miyamizu is known for its high mineral content, however, it contains low traces of iron which can adversely affect the flavor of sake. Miyamizu’s mineral concentration results from geological formations containing shells from ancient marine life of that particular area. The mouth-feel of Miyamizu is smooth, and yet one can taste the minerals as water flows down the throat. The Miyamizu-brewed sake are called Nada no sake or “sake from Nada region”. They’re also called Otokozake or “manly, masculine sake” for their minerality and dry flavored character, with a high acid content. As for Gokosui of Fushimi, this is a much softer water containing lower mineral content. Sake made with Gokosui yields a much gentler and elegant flavor, and therefore is known as Onnazake or “feminine sake”.

In the world of wine, the region where the wine grape is grown and the minerality of the soil it’s grown in, play major roles in determining the classification of the harvest crop, and of the eventual finished brewed wine product. Applying the same idea to Sake, minerality of jozo-yosui is key in understanding sake terroir, the implication of the region’s climate, topography and soil type, along its path to brewed completion.

In the foodservice trade when suggesting sake based on alcohol content and Nihonshu-do, I recommend going a step further to widen the characteristic appeal. Offering wonderful characteristics such as “mouth feel”, flavor sensations derived from minerality such as “crisp-dry flavor” and “gentle and pleasant on the palate”, can help guests make their sake selection process a bit more interesting.