My green tea tastes flat and looks dark in this house

In short

This is a water composition problem rather than a contamination one, and it is distinct from scale in the kettle: the water can be perfectly clean and still be wrong for the leaf. Hard water shifts the colour of the liquor and suppresses aroma, and delicate green, white and yellow teas show it first.

Likely causes, in order

Most likely first. Answer the question under each one before moving on — several of these look alike in the cup and are told apart only by what was done to the leaf.

1. 1. High carbonate hardness in the supply

   Water chemistry

   Check: Do you live in a hard-water area, and does the kettle scale up quickly?

   Fix: Brew the same tea with a filtered or low-mineral bottled water and compare directly. If the difference is obvious, an ion-exchange filter jug is the fix, and it is a bigger improvement for green tea than any change of brewing parameters.

2. 2. Alkalinity darkening the liquor

   Water chemistryInferred by TeaHQ, not established

   Check: Is the colour wrong as well as the flavour — browner or duller?

   Fix: Alkaline water shifts tea pigments towards darker, muddier colours. Filtering lowers it; adding acid is not a solution, because it changes the flavour balance too.

3. 3. A strongly mineral bottled water chosen on the assumption it is better

   Water chemistry

   Check: Are you using a mineral water with a high dissolved-solids figure?

   Fix: Switch to a low-mineral water. This is the opposite of what most people assume, and heavy mineral content flattens aroma in exactly the teas that are bought for it.

4. 4. The tea is the wrong one for this water

   Leaf qualityInferred by TeaHQ, not established

   Check: Does a robust black tea taste fine from the same kettle while the green does not?

   Fix: Hard water suits full black tea and boiled milk tea far better than it suits delicate green tea — it is much of why regional tea styles track local water. Keep filtered water for the delicate teas and stop filtering for the breakfast pot.

5. 5. Water with almost no minerals at all

   Water chemistryInferred by TeaHQ, not established

   Check: Are you using distilled or reverse-osmosis water?

   Fix: Very soft water is its own problem: with nothing dissolved in it the tea comes out thin and hollow. Some mineral content is needed, which is why filtered tap water usually beats both extremes.

Tea types this applies to

• Green tea
• White tea
• Yellow tea

Brewing methods this applies to

• Kyusu brewing (Japanese style) — The Japanese domestic approach to green tea: a moderate quantity of leaf, water well off the boil, short steeps, and two or three infusions from the same leaf with the times adjusted each time.
• Gongfu brewing (gaiwan) — A high-leaf, low-volume, many-infusions approach: a great deal of leaf in a small vessel, steeped for seconds at a time and poured off completely, repeatedly.
• Western brewing (teapot or mug) — A small amount of leaf in a large volume of water, steeped once for a few minutes and then strained off. The approach most English-speaking drinkers already know, and the one most teas sold in the West are made for.

Related problems

Sharing a cause category, a tea type or a brewing method with this one.

• My Japanese green tea tastes of seaweed or fish — A sencha, gyokuro or matcha reads as marine — seaweed at best, distinctly fishy at worst — and it is not clear whether that is the tea or a fault.
• My water is not the temperature the kettle says — The kettle is set to 80 °C and the tea behaves as though it were much hotter or much cooler, and the same setting gives different results on different days.
• There is sediment in the bottom of my cup — A layer of fine dark particles settles out, and the last mouthful is gritty.
• I bought a water filter for my tea and it changed nothing — A filter jug or tap filter was bought specifically to improve the tea, and the cup tastes the same as it did before — with the same dullness, the same film and the same scale in the kettle.
• I cannot taste the difference between my expensive tea and my cheap one — Two teas at very different prices taste much the same in the cup, and the tasting notes on both packets describe things you cannot find.

Sources