The water used for black tea should be 'fresh' above all else. This means it contains a lot of air. Additionally, by distinguishing between 'soft water' and 'hard water' according to the characteristics of the tea leaves, you can encounter a different world of black tea.
Water Hardness
The distinction between soft and hard water is based on the mineral components dissolved in the water. A state where 1 mg of calcium oxide is dissolved in 100 cc of water is considered hardness 1. When using hard water, it is advisable to add 'one cup for the pot' as calcium oxide can hinder the extraction of tannins.
| Category | Characteristics and Recommendations |
|---|---|
| Soft Water (hardness 70 or below) | High extraction ability. Recommended for aroma-focused tea leaves like First Flush and Darjeeling. |
| Intermediate (tap water) | About 70 in Kanto and about 60 in Kansai. Usable for any tea leaves. A water purifier is recommended due to chlorine odor. Ideal for Ceylon varieties. |
| Hard Water (hardness 120 or above) | Low extraction ability, suppressing astringency. Good for strong-flavored tea leaves like Assam. Most of Europe has hard water. |
What is Fresh Water?
It is important that the water contains fresh air. Jumping occurs because the air in the water becomes active. Stale water or mineral water (which loses freshness during transport and often contains hard water) is unsuitable. Water that has been boiled twice or overheated is also not suitable as it increases calcium concentration and loses air.
If using tap water, boiling it for about three minutes after bubbles the size of a 5-yen coin appear will sufficiently remove chlorine odor (using a water purifier allows for a shorter time). Water from a thermos is unsuitable as it is older and at a lower temperature. The soluble components of black tea cannot be extracted unless the water is at least 90 degrees Celsius.
Most tap water in Japan is soft, so the conditions for enjoying black tea are well met. This means that better quality water is available nearby compared to low-freshness mineral water.