What is meant by the term nansui in sake making?

Nansui refers to soft water in the context of sake making. Soft water is characterized by low mineral content, including lower concentrations of calcium and magnesium. This type of water is particularly beneficial in sake production because it allows for a more delicate fermentation process, which can lead to cleaner and smoother flavor profiles in the final sake product.

In many regions of Japan, soft water is favored for brewing sake because it promotes specific yeast activities that enhance fruity and floral aromas, which are often sought after in high-quality sake. Additionally, water composition is crucial in determining the overall character and quality of the sake, making the distinction between hard and soft water significant in the brewing process.

Understanding this term is essential for professionals in the sake industry, as the water used can greatly influence the end product's taste and quality.