Butterfly Pea Flower Tea: The Blue Tea That Changes Colour
Few drinks are as eye-catching as butterfly pea flower tea. Made from the dried flowers of Clitoria ternatea, a climbing vine that grows easily in Thailand’s warm climate, it brews a vivid, ink-blue cup with a mild, earthy floral flavour.
A Thai kitchen staple
In Thailand the flower is called dok anchan. Long before it became popular in cafés around the world, it was used at home to colour rice, sticky-rice desserts and cold drinks a natural blue.
Why it changes colour
The blue comes from natural plant pigments called anthocyanins, which change colour with acidity. Add lemon or lime juice and the tea shifts from blue to violet; add more and it moves towards pink. It is the same kind of reaction that makes red cabbage change colour when cooked with vinegar.
How to brew it
- Place one tea bag in a mug and pour over 250 ml of freshly boiled water.
- Steep for 3–5 minutes, until the colour is a deep indigo.
- Enjoy it plain, or add a squeeze of lemon or lime for colour and a little sharpness.
Ways to enjoy it
- Iced: brew double-strength, cool and pour over ice with mint.
- Layered: pour cooled blue tea gently over lemonade for a two-tone drink.
- With honey and ginger: a slice of fresh ginger adds warmth on a cool evening.
