‘Next to water tea is the beverage most widely in use throughout the world' claimed the Encyclopaedia Britannica in 1910. There's no doubt that without water, life on earth as we know it wouldn't exist. More importantly, tea as a beverage wouldn't exist.
But just how important is the water we use for tea? One Chinese proverb claims "water is the mother of tea," suggesting both a generative connection where tea comes from water, and a nurturing one, where the right water will perhaps voax out a tea's best qualities.
Just about every brewing guide suggests that freshly drawn water is the best for tea. Today that means filling your kettle with new water from the tap before you heat it rather than reheating any water still sitting in the vessel. This has to do with the oxygen available in the liquid; cold, fresh water contains more oxygen and the more oxygen there is, the better the flavour – or so the science goes.
Lu Yu, author of early tea-drinking guide The Classic of Tea, went deeper and stated a hierarchy of the best water to use for tea. Water from a mountain stream (especially "slow-flowing streams, stone-lined pools or milk-pure pools") topped the list, followed by river water, then water from a well.
While placing well water at the bottom is understandable given the likelihood its stillness has reduced available oxygen, why would Lu Yu elevate mountain water? It turns out minerals such as calcium, magnesium, sulphates and salts influence the tea. Traces of these minerals can enhance the complexity, flavour and mouthfeel of black teas and oolongs. On the flip side, more delicate white and green teas seem to taste best when steeped in water with lower mineral content where minerality does not overpower the tea.
Tea lore suggests that using water from where the tea is grown gives the best flavour as it comes from the same ecosystem – a kind of synergy, if you will. For most of us that's not practical, so if you're not using bottled mountain spring water, soft cold tap water is usually fine. If you're picky, most commercially available domestic filters will remove fluoride and chlorine, two enemies of tea.
For the most part, I'm grateful that we have access to clean water when parts of the world don't. As you prepare to brew your tea this week, think about how wonderful water is for giving us the gift of tea.
