Variable temperature kettles

Choosing a variable temperature kettle

A variable temperature kettle heats water to the exact temperature you want, not just a rolling boil. That is the difference between a bitter morning matcha and a smooth one, and it is handy for green and white teas, coffee, and cooling water for baby formula.

Most models offer presets such as 70, 80, 90 and 100°C, though some step in 5°C increments and a few reach as low as 40°C.

Models mainly differ in their temperature range, whether they keep water warm, what the inside is made of, how much they hold, and how noisy they are. To compare standard models, browse our kettles. To match your worktop, browse toasters.

How the temperature settings work

Most models use presets you select with a button or touch slider, and many remember the last setting, so there is no need to choose it every time. If you mainly want boiling water, models generally default to 100°C.

Water temperatures for different teas

As a general guide, the more delicate the tea, the cooler the water. Boiling water can scorch delicate leaves and taste bitter, while robust teas need a full boil to brew properly:

• Green tea: around 70 to 80°C. Boiling water turns it bitter fast, so a lower setting keeps it smooth and sweet

• White tea: around 75 to 85°C, as delicate buds brew better just below boiling

• Matcha: around 70 to 80°C. Too hot and it turns bitter and flat; a cooler pour keeps the sweetness and umami

• Herbal teas and fruit infusions: a full boil at 100°C, usually with a longer steep for a fuller flavour

• Black tea and coffee: close to boiling, around 90 to 100°C

If your kettle only offers presets of 70, 80, 90 and 100°C, choose the nearest setting below boiling for green tea, white tea and matcha.

Using the keep-warm function

Keep-warm holds water at your chosen temperature, usually for about 30 minutes, before switching off. It can use less energy than re-boiling, and it keeps a set temperature ready for green tea or matcha. On some models keep-warm is set during heating rather than before or after.