In a bottle of sake, about 80% is pure water. Water is used in all the steps of the brewing process including washing, soaking, steaming the rice, addition to the fermentation tanks and dilution before bottling. That adds up to almost 30 times the amount of rice by weight. It definitely warrants some attention! The water quality plays an important role in defining the quality and character of a sake.
Most of the traditional sake brewing locations are located near good supply of water source such as rivers, wells, or springs. Two of the most renowned location of high-quality brewing water comes from the Nada region in the city of Kobe in Hyogo prefecture and Fushimi in Kyoto prefecture.
Japanese waters are generally soft because of the low presence of limestone in the archipelago which filters the waters as it makes its way to the surface. But having said that it is entirely possible to brew sake from “harder” waters. It is the composition of the water that is of more importance.
Hard waters contain more minerals like potassium, phosphorus acid and magnesium. These three minerals are desirable to aid propagation of yeast in the yeast starter, assist proper development of good rice koji and speeds up fermentation.
Water which contains iron and manganese are considered unsuitable and are detrimental to sake production. Iron is the most detrimental because it darkens the colour of sake and will affect both the flavour and aroma profile of sake. Manganese also causes a chemical reaction that discolours and de-luster the appearance of a sake. Brewing water must be tasteless, odourless, colourless and clear. It must not contain organic substances or harmful microorganisms. Many breweries take precaution by using filtered well water.
The water from Nada prefecture has long been famous for its suitability for sake brewing. It is known as Miyamizu. These waters can be traced back to rainfalls that falls on the Rokko mountains and as the underground water flows through the sub-strata, the iron reacts with oxygen and is deposited, resulting in a water that is low in iron. The same process accumulates potassium and phosphate which is beneficial. Miyamizu water is classified as hard water and in Japanese is known as “kohsui”. Sake from Nada are robust, sharp and dry. These sakes can be classified as masculine sake or in Japanese “Otoko-sake”.
On the other hand, water from Fushimi area of Kyoto is relatively low in mineral content and softer, known as “nansui”. With a lower mineral content, soft water brewing process were successfully developed so that even with soft water, it was possible to produce a mellow style of sake. Their soft water favours a slow fermentation which is necessary for the fruity ginjo aromas to develop. Sake made with soft water is called “onna-zake” or feminine sake. Such sake is usually fine textured and smooth on the palate.
After pressing the sake, the alcohol content of the sake may be as high as 22%. Most sakes are diluted with pure water to decrease the alcohol content to around 15-16%. With a lower alcohol content, it is easier to discern and enjoy the flavours and aromas of fine sake.
The softer the water used for dilution, the mellower the taste of the sake. This same trait is reported for those whisky drinkers too. Adding hard water to your whisky gives you a sharp bitter taste while using distilled water gives you a soft/ mild taste. But there are exceptions to this practice of dilution over the last decade where brewers produce “muroka nama genshu” sakes which are un-pasteurized, un-charcoal-filtered and un-diluted, with the intention of keeping it as close to the original natural state as possible.
So the next time you take a sip of your sake, it’s good to contemplate about its water component.
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