As a rule of thumb, there is one teaspoon of tea per cup (250 ml) of water in tea and, therefore, the quality of the water plays a significant role. I think focusing not only on tea leaves but also on considering the water should lead to new and improved experiences with tea.
I have worked with a tea and water sommelier to explore this world. Michael Hemling is a certified tea sommelier and a graduate of the Fine Water Academy I am running together with Martin Riese. As a final project of his extensive studies with us, we asked Michael to conduct experiments with water and tea.
We used Chinese oolong tea, and it was amazing to see how the color of the tea changes with waters of different Minerality being used. Super low Minerality created the classic tea color while increasing the TDS of the waters used darkened the tea significantly. Tastewise, the super low minerality water was also preferred as it allowed the tea to express itself perfectly. Increased TDS started competing with the tea, and very high Mineralization completely overwhelmed the tea. Interestingly, distilled water with a TDS of almost 0 also didn't express the tea well and had a very disappointing taste.
We recommend using a super low mnerality (TDS > 50mg/l) still water from a natural source with a neutral pH, just above 7. Don't use tap water due to the effect of chlorination on tea. Softened and reverse osmosis water also leads to compromised taste profiles, and distilled water should never be consumed or used other than in equipment.
