Sake nerds are weird people. We get together and talk about yeast numbers and often, how hard the water is. I’m going to indulge my inner geek and talk about this exciting topic…
Water hardness is the amount of calcium and magnesium in the water. These minerals come from rocks, such as limestone that dissolves in the system. Japan, as a country, has generally soft water. The average is 61 mg/L, whereas it’s 120 mg/L for the US. For those of us in the West Coast of Canada, the water is unusually soft, where the source is mostly from mountain lakes fed by glaciers and snowmelt, at around 5 mg/L for Vancouver. Why does this matter to sake?
To put is simply, harder water promotes vigorous fermentation, as calcium is necessary for enzyme activity. This often leads to sakes that are thicker and fuller bodied. It’s suitable for Junmai and Yamahai styles of sake, which have a solid backbone of acidity. Nada, in Kobe, has been traditionally raised as an example of a hard water source. Fushimi, Kyoto, for soft water. Below are examples of water from some of my favourite breweries:
Toronto: 128 mg/L
Vancouver: 5 mg/L
Tengumai: 105 mg/L
Fukumitsuya: 178 mg/L
Hakkaisan: 43 mg/L
Soft water sake has been traditionally called “onna-zake” (“woman sake”) and hard water sake “otoko-zake” (“man sake”). Yes, it’s kind of sexist and gender specific but most of the time, it makes sense. More often than not, hard water sakes are thick and full-bodied, like the Burt Reynolds of sake. And more often than not, soft water sakes are lighter and leaner, like…I’ll leave that to your imagination.
This is a bottle of water I bought at Narita airport and it’s supposedly water from Mt. Fuji. It lists the water hardness, which my inner geek finds super interesting: 32 mg/L. So I imagine that it’s flowed through the mountain a bit, picking up minerals along the way, which is why it’s not super soft.
Water hardness doesn’t tell you everything – there are SO many factors when brewing sake that contribute to the final taste that it can’t just be about the water. But as it makes up 80% of the final product, I think it’s at least worth a thought or two.