In the famous 'Tea Classics' book written by Lu Yu (8th Century), much of the book was dedicated to water. And for good reason. In China, Water is called the 'mother of tea' and it is fundamental to the tea experience. In fact, I would go as far as saying that the water is nearly as important as the tea leaves.
Often I have sourced tea in China and realised that it tastes very different when I am in London. The Spring water that the farmers may be using certainly can provide a softer and clearer environment for the tea aromatics to express themselves. One viewer on YouTube took my analogy of music and brewing and said that water represents the space for the music. A violin played in small room will sound different to one played in a concert hall. For all teas there is the perfect reverb to show off its character.
I am in deep experimentation about water so this blog will be updated when I have more conclusions. But this is what I know so far:
So what kind of water is best for tea? That's not such a simple question to answer so let's begin with which water you should avoid completely.
Distilled or RO Water
Tea needs minerality for texture and flavour. Brewing with distilled water or RO water produces a tea that is vacant and flavourless. If you have these systems installed then you must try to find a way to remineralise the water by adding Maifan stones or something similar.
Heavily Chlorinated Tap Water
Yes it tastes like Chlorine and no that is not how tea should taste. Get a water filter jug or ideally install a water filter for your whole home so that you can shower without breathing in the chlorine (which is more dangerous than drinking).
Here are the water parameters that we are playing with and some general observations:
Tea leaves prefer neutral to slightly acidic water in my opinion. Aim for between 6 and 7 pH value if possible.
The Total Dissolved Solids is a figure showing how much 'stuff' is in tea but it does not represent what the balance of those minerals are so can be quite a meaningless number. However, in my observations, water with a TDS of between 120-170 seems to produce nicer texture tea. Usually this means that you should be searching for Spring wtaer on the safter side of things or to use a water softener for tap water.
The aeration of water definitely will have an effect on how the water extracts and if it oxidises the tea faster. General consensus is that you want to find tea with high dissolved oxygen and try not to boil your water too much as this may drive off more oxygen. I have always questioned this theory because my understanding is that the majority of oxygen is driven out of water past 70 degrees (165 farenheit) but we tested the theory in this video.
As I said, there will be more to follow on these water studies!