Sencha spotlight: Brewing Japanese green tea with different brands of water

Does the flavour profile of your tea change depending on the type of water used? We decided to test this out by using different brands of mineral water with different hardness levels. (This article was originally written in Japanese by Natsuki Shibayama)



Recently one of our regular customers informed us that the tea she bought from d:matcha tasted different when she tried to brew it at home and the only differenced during the brewing process was: the water.


We felt this difference before, during our tea-trip to Paris, where we had to purchase bottled water specifically labeled as "soft water" to brew our tea. Furthermore, when we were running our store in Kyoto city, we also realised there was a stark difference in the brew simply because the tap water was different.

Clearly the assumption that most of the tap water found in Japan is soft water was wrong! Thus we decided to do an experiment together to see if there was really a difference.



To start with, "hardnesss" is the term used to indicate the levels of calcium and magnesium found in water. Water with a hardness level of 100 or less are categorised as "soft water". While water with a hardness level of 100 to 300 are categorised as "medium hard water", and finally water with a hardness level of 300 and above are classified as "hard water". Ideally the water should have a hardness between 50mg to 80mg when brewing Japanese green tea.



The different types of mineral water that was used are:

  • Contrex - 1468mg/L

  • Evian - 304mg/L

  • Volvic - 60mg/L (Similar hardness to tap water in Tokyo)

  • Alkaline Ions - 55mg/L

  • Irohasu - 40mg/L (Similar hardness to tap water in Osaka and Kyoto)

  • Fresh water from Mt. Okuoyama - 20mg/L

  • Water from Wazuka - 11mg/L (We were amazed by the low mineral content!)

  • Hot spring water form Kagoshima - 1.7mg/L

Perimeters for the experiment

Type of sencha used: 2020 Okumidori (Shaded for 6 days)

Amount of water & temperature: 80ml at 60°C (approximately. 140°F)


Steeping time: 90 seconds


When brewed with water from Wazuka Town, our okumidori (shaded for 6 days) has a very well balanced flavour profile. The astringency of tea and umami balance one another out, especially when first brewed at a low temperature.

Let's start!

We started off with the imported water:

Contrex (1468mg/L)、Evian (304mg/L)、Volvic (60mg/L) Surprisingly, the tea brewed with these three brands of water turned out to be better than we expected! We were able to distinct the umami from the bitterness. Personally I felt that it was much better than the water we has used in France.


Alkaline Ion water (55mg/L)、Irohasu (40mg/L)


The tea brewed from water with these hardness level did not have a distinct flavour of umami or bitterness. Perhaps if we had prepared water of a higher temperature (80°C ), the brew would have tasted better. (We used this technique to improve the quality of our tea, especially during tastings, in Kyoto City!)