Best Loose Leaf Tea for Hard Water Areas

In short: hard water, which runs from the taps in most of London, the South East and East Anglia, is high in calcium and magnesium. It dulls the flavour of tea, turns it cloudy and leaves that familiar film on top of the mug. Strong, malty black teas such as Assam and breakfast blends cope best, especially with milk. For green, white and oolong teas, use filtered water, fresh from the tap, and boiled only once.

If your kettle grows a white crust within weeks, you live in a hard water area. The good news is that you do not have to give up on good tea. You just need to choose the right leaf and make a few small changes to how you brew.

How hard water changes your cup

Hard water carries dissolved minerals, mostly calcium and magnesium carbonates, picked up as rainwater filters through chalk and limestone. Those minerals react with compounds in tea, and you can see and taste the result:

• Scum on top: a thin, oily-looking film that breaks into flakes when you stir. It forms when the minerals bind with the tea's natural compounds as the cup cools.
• Cloudy, darker liquor: the tea looks muddy rather than clear and bright.
• Flat flavour: hard water mutes aroma and sweetness, so a delicate tea tastes thin and a little chalky.
• Limescale: the same minerals build up in your kettle, which also affects the taste over time.

Soft water areas, such as most of Scotland, Wales, the North West and the South West, rarely see these problems. That is one reason the same tea can taste quite different in Manchester and in London.

Which teas cope best with hard water?

Some teas are simply more forgiving. Bold, full-bodied black teas have enough strength and malt to stand up to the minerals, and milk hides most of the film.

For an everyday mug in a hard water area, our favourites are:

• English Breakfast: a classic full-bodied blend that keeps its colour and strength with milk.
• Assam Harmony: rich and malty, the kind of Assam that shrugs off minerals.
• Irish Breakfast: strong and brisk, ideal if you like your tea with plenty of milk.

You will find more strong brews in our black tea range, and if you want the full method for a proper strong cuppa, see our guide to builder's tea with loose leaf.

6 simple fixes for better tea in hard water

You do not need expensive kit. These changes make the biggest difference:

1. Use a filter jug. A standard jug filter takes out much of the calcium and chlorine. It is the single most useful change, especially for green and white tea.
2. Use fresh, cold water every time. Do not reboil water that has been sitting in the kettle; it concentrates minerals and loses oxygen, which makes tea taste flat.
3. Boil only what you need. Less standing water means less limescale and a fresher brew.
4. Descale the kettle regularly. Every 2 to 4 weeks in a hard water area. Our guide on how to clean a tea kettle covers citric acid, vinegar and lemon.
5. Drink it fresh. The film forms as tea cools, so pour and enjoy rather than letting a cup sit for 20 minutes.
6. Add milk or a slice of lemon. Milk hides the film in black tea. A little lemon in a cup without milk reduces the scum too, though it changes the flavour.

Should you use bottled water?

For everyday black tea, filtered tap water is enough. For a special green tea, such as a Japanese sencha or a fine white tea, a low-mineral still bottled water can bring out sweetness that hard tap water hides. Check the label and pick one with low total dissolved solids. Avoid distilled water: with no minerals at all, tea tastes flat and lifeless.

Brewing tips that help in hard water

A few small adjustments to strength and timing go a long way:

• Use a little more leaf for black tea: about 3 g (a heaped teaspoon) per 250 ml mug, so the flavour cuts through.
• Keep to the right time: 3 to 5 minutes for black tea. Longer steeps in hard water turn the cup bitter and dark rather than stronger.
• Warm the pot or mug first so the temperature stays steady while the tea brews.
• Lift the leaves out when the time is up. A mug or pot with a removable infuser makes this easy.

Frequently asked questions

Why does my tea have a film on top?

That film forms when the calcium and magnesium in hard water bind with natural compounds in tea as it cools. It is common in hard water areas and is reduced by filtered water, drinking the tea fresh or adding milk or lemon.

Which part of the UK has the hardest water?

London, the South East and East Anglia generally have the hardest water, because their supply runs through chalk and limestone. Scotland, Wales, the North West and the South West mostly have soft water.

Does a water filter jug improve tea?

Yes. A jug filter removes much of the calcium and chlorine, so tea tastes brighter and forms less scum. It makes the biggest difference for green, white and oolong teas.

What is the best tea for hard water?

Strong, malty black teas such as Assam, English Breakfast and Irish Breakfast cope best, especially with milk. Delicate green and white teas suffer most and are best brewed with filtered water.

Should I use distilled water for tea?

No. Distilled water has no minerals, so tea brewed with it tastes flat. Filtered tap water or a low-mineral bottled water gives a much better cup.