Soft water, hard water and why your tea tastes different on holiday
If your tea has ever tasted wrong in a hotel, it was probably the water. Tea is about ninety nine percent water, and the minerals in it change the colour, the strength and the taste of the cup more than most people realise. Here in Glasgow we have very soft water, and it is one of the reasons Scottish Breakfast is blended the way it is.
What soft and hard mean
Hard water carries a lot of dissolved calcium and magnesium, picked up from chalk and limestone. Most of the south and east of England is hard. Soft water has very little, because it has run over granite and peat. Most of Scotland, Wales, the north west of England and Cornwall is soft.
You can tell which you have by the kettle. Limescale means hard. A kettle that stays clean for years means soft.
What it does to the cup
Soft water pulls flavour from the leaf quickly and gives a bright, clear brew that tastes of the tea. It can make a strong tea taste stronger and a delicate tea more delicate, which is why Darjeeling and the greens are lovely here.
Hard water does the opposite. The minerals bind with tannins, the tea brews darker and duller, a film forms on the top, and a scum can gather at the edge of the mug. The tea can taste flat and a bit chalky, and strong black blends lose their edge. This is the real reason English Breakfast was built brighter and Scottish Breakfast heavier. Each was blended for the water it was going to meet.
Brewing in hard water
If you are in a hard water area, a few things help. Use a filter jug, which removes most of the hardness and makes an obvious difference. Brew a minute longer or use a touch more leaf. And pick teas with some weight to them, Assam, Scottish Breakfast, Lapsang, the rooibos family, which stand up to it better than light greens and whites.
Brewing in soft water
Soft water needs less. You may find you can use a shade less leaf, and that green teas want slightly cooler water than the label says, because they brew so readily. If a tea seems too strong or a touch harsh, shorten the time before you blame the leaf.
Bottled, filtered and boiled twice
Filtered tap water is the best everyday choice almost everywhere. Bottled still water varies, some is very hard, so check the label for low mineral content if you go that route. Distilled water makes a flat, lifeless cup, as tea needs a little mineral content to taste right. And boiling the same water twice does not harm anything, whatever your gran said, though fresh water does carry a little more oxygen and brews a touch livelier.