軟水

1. Origins, structure, and basic meaning

• Structure: The spelling is 軟水, read なんすい, and it combines 軟, meaning soft, with 水, meaning water.
• Basic usage: The basic sense of 軟水 is soft water with a relatively low concentration of calcium, magnesium, and other hardness-producing minerals.

2. Common pitfalls and similar expressions

• Low mineral hardness rather than a tactile quality
  • Both examples use the form 軟水. It is a classification based on low water hardness, not ordinary softness to the touch, and it contrasts with 硬水.
• Separate hard-water samples and broth flavor comparison
  • 実験では硬水と軟水を別々の容器に入れた。 — In the experiment, we placed hard and soft water in separate containers.
  • 料理教室で軟水を使っただしの味を比べた。 — In cooking class, we compared the flavor of broth made with soft water.