Best Water for Green Tea: Tap, Filtered or Bottled?

Before buying another bag of tea, try changing the water for one cup. It is an easy thing to overlook when all our attention goes to the leaves. I would make that small comparison before spending money on a special kettle or a cupboard full of bottled water.

What is the best water for green tea?

There is no bottle I would tell everyone to buy. Start with safe drinking water you enjoy on its own. Ippodo's water guide takes that approach too. For its Japanese teas, it says softer water brings out umami more readily, while harder water gives a crisper character. Different does not automatically mean worse.

The same guide advises against distilled water for brewing its teas because removing the minerals affects the taste. That is brewing advice, not a reason to replace your household drinking water.

Tap, filtered or bottled: what to compare

Three practical starting points

Water	A useful first check	For your comparison
Tap	Use it only if it is safe to drink.	Your everyday baseline.
Filtered tap	Use the filter according to its maker's instructions.	Test the filter you have, not an imagined “perfect” water.
Still bottled	Note the brand so you can repeat the cup.	Try a small quantity before buying more.

This compares taste, not water safety. A nicer-tasting cup does not show that water is safe.

Keep the test fair

1. Keep: the same tea, fresh leaf amount, water volume, temperature and time.
2. Change: only the water used for cup A and cup B.
3. Compare: taste at a similar comfortable temperature and note your preference.
4. Decide: choose the cup you enjoy. No clear difference? Keep your usual water.

Try two cups before buying anything

Use your usual tap water, if it is safe to drink, and one alternative: water from a filter you already own, or a still bottled water. Keep the tea and recipe the same. A filtered cup only tells you about that particular filter and water; it does not prove that all filtered water tastes better.

Label the cups A and B and use similar cups if you can. The steps above keep the comparison focused on the water.

Do not use the leaves from cup A again for cup B. That would compare two infusions as well as two waters.

A tiny tasting note

Tea and recipe: __________

Water A: __________   Water B: __________

What I noticed: aroma / bitterness / drying feeling / no clear difference

What I would use again: __________

If both cups taste unpleasantly bitter, check the brew too: Ippodo’s troubleshooting advice covers leaf amount, temperature and time.

Check the mug before blaming the tap

If you put more water in one cup, you have changed the strength too. As I explain in why green tea can taste watery, the size of the serving matters. Measure your usual fill rather than guessing from the mug's appearance.

Use the same open packet for both cups as well. My guide to storing green tea covers keeping it closed between uses.

If the difference is too small to care about, keep your usual water. There is no prize for making a morning cup more complicated.

If the change you notice is color rather than taste, see why brewed green tea turns brown. It separates a change after standing from the color of the freshly brewed tea.