The last time I visited my favorite tea house, I asked my tea dealer a question. “Why is it that every time I buy tea here and make it at home, it doesn’t taste as good as when you do it?” “Simple,” she answered. “It’s the water.” “But couldn’t it also be your technique or the equipment you use? Maybe you’re doing something right that I’m doing wrong.” That’s when she told me about another customer with a similar question. “I made some tea at his home with the same equipment that I have here. I did everything the same. But he didn’t have my water, so the tea was different.” These differences are subtle, the kind you might not notice if you’re brewing flavored tea, making a pitcher of iced tea, or planning to add lots of milk and sugar. But in fine tea, the kind that’s meant to be drunk straight, subtlety is everything. Brew a tea one way and it might taste nice. Brew it with some extra care and it can floor you with its complexity, aroma, and finish that lingers for minutes after each sip. Ask tea experts about brewing and they’ll tell you how your source of water is critical, how better water turns a good tea great and bad water can make even pricey tea taste sour and acrid. Anecdotally I’ve seen this claim in action, but I’ve never put numbers to it—until now. Can we quantify the impact of water source on tea? The Claim While advice varies from tea person to tea person, the general argument all comes down to what’s in your water besides water. That includes minerals endemic to a water supply, additives like fluorine, and even dissolved solids from old pipes. Too many minerals and your water is “hard,” which can add funky metallic flavors to tea. Absolutely pure water like distilled is no good either, tea people claim—it’s so bland it can make tea taste dull. Water for tea should have a neutral pH so it doesn’t turn the tea sour or bitter. And it should be freshly boiled, as water that’s been boiled again and again can absorb off flavors from the air around it. That’s a lot to think about before you even pick out a tea to brew. And it’s a lot of variables to test. But a good starting point is the three sources […]