Influence to Japanese sake determined by the quality of water
Approximately eighty-percent of Japanese sake ingredients consist of water. Therefore, the quality of water greatly influences the quality of Japanese sake.
Water used to produce sake is generally referred to as sake brewing water, broadly divided into brewing water and bottling water. Also, brewing water is further divided into washing water, soaking water, brewing water, and miscellaneous water; while bottling water is further divided into wash bottle water, addition water, and miscellaneous water. Among these waters, the brewing water - the direct ingredient of sake - is no doubt the most important quality of sake.
However, sake rice will absorb components dissolved in the water used while washing and soaking the rice in water, thus water used for soaking the rice must not contain components harmful to sake production. Also, addition water refers to water that adjusts the alcohol concentration of unprocessed sake, so of course, the water quality must be equivalent to the water quality of the brewing water. The containers and tools used, miscellaneous water used to wash the bottles, and anything that comes in direct contact with sake also requires high quality water.
Generally, water is categorized as hard and soft water. Hard water refers to water containing significant mounts of alkaline earth metals (calcium ion and magnesium ion), while soft water contains minimal amounts of these metals. Soft water is more suitable for producing Japanese sake, for the sake quality produced using soft water generally makes the sake quality light and clean. However, when using the expressions soft vs. hard water, it must be taken into consideration that most of Japan’s natural waters mostly fall under the “soft water” category compared to foreign waters. For example, the most renowned Japanese sake brewing water “Miyamizu” (Nada spring water) is categorized as having the highest hardness of Japan’s brewing water, yet still incomparably low in hardness compared to renowned waters in Europe, etc.
According to general water hardness and softness standards, hard water is defined as above 20 degrees, medium-hard water is defined as between 20 ~ 10 degrees, while soft water is defined as below 10 degrees. According to the National Tax Agency’s analysis method of categorizing sake brewing water by hardness, high hard water is defined as above 20 degrees, hard water is 20 ~ 14 degrees, medium hard water is 14 ~8 degrees, light hard water is 8 ~ 6 degrees, and medium hard water is defined as between 6 ~ 3 degrees, and soft water is defined as below 3 degrees. The hardness of “Miyamizu” (Nada spring water) is defined as between 9 ~ 11 degrees, yet categorized as medium hard water according to the later classification standards, yet still fall under “soft water” according to global standards.
The suitability of the water quality as brewing water depends not only on the water hardness and existence of harmful components, but the degree of contained components effective for koji mold and yeast to function are also a major condition, for which the “miyamizu” (Nada spring water) is superior in this regard.
Water used to produce sake is generally referred to as sake brewing water, broadly divided into brewing water and bottling water. Also, brewing water is further divided into washing water, soaking water, brewing water, and miscellaneous water; while bottling water is further divided into wash bottle water, addition water, and miscellaneous water. Among these waters, the brewing water - the direct ingredient of sake - is no doubt the most important quality of sake.
However, sake rice will absorb components dissolved in the water used while washing and soaking the rice in water, thus water used for soaking the rice must not contain components harmful to sake production. Also, addition water refers to water that adjusts the alcohol concentration of unprocessed sake, so of course, the water quality must be equivalent to the water quality of the brewing water. The containers and tools used, miscellaneous water used to wash the bottles, and anything that comes in direct contact with sake also requires high quality water.
Generally, water is categorized as hard and soft water. Hard water refers to water containing significant mounts of alkaline earth metals (calcium ion and magnesium ion), while soft water contains minimal amounts of these metals. Soft water is more suitable for producing Japanese sake, for the sake quality produced using soft water generally makes the sake quality light and clean. However, when using the expressions soft vs. hard water, it must be taken into consideration that most of Japan’s natural waters mostly fall under the “soft water” category compared to foreign waters. For example, the most renowned Japanese sake brewing water “Miyamizu” (Nada spring water) is categorized as having the highest hardness of Japan’s brewing water, yet still incomparably low in hardness compared to renowned waters in Europe, etc.
According to general water hardness and softness standards, hard water is defined as above 20 degrees, medium-hard water is defined as between 20 ~ 10 degrees, while soft water is defined as below 10 degrees. According to the National Tax Agency’s analysis method of categorizing sake brewing water by hardness, high hard water is defined as above 20 degrees, hard water is 20 ~ 14 degrees, medium hard water is 14 ~8 degrees, light hard water is 8 ~ 6 degrees, and medium hard water is defined as between 6 ~ 3 degrees, and soft water is defined as below 3 degrees. The hardness of “Miyamizu” (Nada spring water) is defined as between 9 ~ 11 degrees, yet categorized as medium hard water according to the later classification standards, yet still fall under “soft water” according to global standards.
The suitability of the water quality as brewing water depends not only on the water hardness and existence of harmful components, but the degree of contained components effective for koji mold and yeast to function are also a major condition, for which the “miyamizu” (Nada spring water) is superior in this regard.
水質が与える日本酒への影響
日本酒の成分の約80％は水である。したがって、水のよしあしは当然、酒の品質に大きく影響する。
酒造りに用いる水を総じて酒造用水というが、この酒造用水は、醸造用水と瓶詰用水に大別される。また、醸造用水はさらに、洗米・浸漬用水、仕込用水、雑用用水に、瓶詰用水はさらに、洗瓶用水、割水用水、雑用用水に区分される。これらの用水のうち、直接酒の原料となる水（仕込用水）が最も重要なことはいうまでもない。しかし、たとえば米は洗米・浸漬の過程で水中に溶けている成分を吸着してしまうので、洗米・浸漬用水にも、酒造りにとって有害な成分を含まない水を使わなければならない。また、割水用水というのは原酒のアルコール濃度を調整するために加える水だから、当然のことに、仕込用水と同レベルの水質が要求される。醸造に際して使用する容器や道具類、瓶の洗浄に使用する雑用用水でも、酒と直接接触するものを洗浄する場合には良質の水が要求される。
一般に、水は硬水と軟水とに分けられる。硬水とはアルカリ土類金属（カルシウムイオンとマグネシウムイオン）を多量に含む水で、軟水はその含量の少ない水である。日本酒の仕込み水としてどちらが適しているかといえば軟水で、一般に、軟水で仕込む日本酒の酒質は軽くきれいになるといわれる。しかし、この軟水、硬水の表現では、わが国の自然水は海外の水と比較すればほとんどが「軟水」の部類に入る、という事情も考慮しなければならない。たとえば、日本酒の仕込み水の中で最も有名な灘の「宮水」の硬度は、わが国の醸造用水の中では最も硬度高い部類に入るといわれるが、欧米などの銘醸地の水とは比較にならないほど硬度が低い。
一般的な硬・軟水の基準では、硬水は硬度20度以上、中硬水は20～10度、軟水は10度以下とされるが、国税庁所定分析法による酒造用水の硬度分類では、高硬水・20度以上、硬水・20～14度、中硬水・14～8度、軽硬水・8～6度、中軟水・6～3度、軟水・3度以下となっている。「宮水」の硬度は9～11度で、後者の分類では中硬水の部類に入るわけだが、世界的に見れば「軟水」ということだ。
水質の醸造用水への適否は、硬度や有害成分の有無だけでなく、麹カビと酵母の働きに役立つ有効成分がどれくらい含まれているかも大きな条件になり、その点でも「宮水」は優れている。
