Butterfly Pea Flower Tea

Butterfly pea flower tea, in summary: The blue drink that turns purple with lemon: real pH chemistry, caffeine free and gentle, with the superfood claims put to the test.

Butterfly pea flower tea is the bright blue drink that turns purple when you add lemon, and that colour change is doing most of the work in its popularity. A careful guide separates the two things that get sold together here: the real, harmless and rather lovely natural dye chemistry, and the considerably overstated “superfood” marketing, with its brain and anti ageing promises, that has been layered on top of it.

Last reviewed by the teas.co.uk team in May 2026.

What butterfly pea flower tea actually is

It is a tisane, not tea: an infusion of the dried blue flowers of Clitoria ternatea, a plant grown across South-East Asia, with no tea leaf and therefore no caffeine. On its own it tastes mild, slightly earthy and faintly woody, which is clearly part of the point, the flavour is gentle so it is often blended with lemongrass, ginger or fruit, and it is frequently used as much for colour as for taste. Anthocyanin pigments give the striking blue, and the colour moves with pH: stir in an acid like lemon and it turns towards purple and pink, which is plain chemistry rather than a gimmick or an additive.

What the health research shows

This is where the careful reading matters. The colour change is real. The caffeine-free, low-calorie, pleasant-to-drink part is real. The claims for memory, ageing, fat burning and the like do not hold up at the level the marketing suggests; they mostly rest on laboratory or animal studies of concentrated extracts, which say little about a cup of flower infusion, and calling them proven would be the very overclaim this wiki refuses. Anthocyanins are plant pigments found in many colourful plants, and that does not turn any of them into a treatment. The summary: a nice, harmless, caffeine-free, photogenic drink with no demonstrated special powers in cup form. That is not a criticism; it is just the accurate label.

How to use it well

Brew the dried flowers in just-off-boil water for around five minutes; it is forgiving like other flower infusions and you cannot easily make it bitter. The fun, and the practical appeal, is the colour: brew it strong for a natural blue base in iced drinks, lemonades and mocktails, and squeeze in citrus at the table so the colour changes as people watch. As a hot drink it is best with a flavour partner (lemongrass, mint, ginger, a little honey) because plain butterfly pea is mild. It also works as a natural food and drink colouring where you would otherwise reach for synthetic blue.

Clear cautions

For general use it is considered low risk in normal drinking amounts, which is worth saying clearly because it is one of the gentler tisanes. The fair, specific notes: it is caffeine-free so it suits the evening and caffeine-avoiders; like many botanicals it is sensible to be cautious in pregnancy and to treat concentrated extracts differently from a weak flower infusion; and it should be enjoyed for what it is rather than taken "for" a condition. Those are flags, not alarms, and they are the necessary counterpart to the colour-trick enthusiasm.

Choose butterfly pea flower tea for the colour and the caffeine-free gentleness, which are both real and both fun, and ignore the superfood story, which is not. Brew it strong, partner it with flavour or citrus, enjoy the blue-to-purple party trick, and treat it as the harmless, pretty, modest drink it actually is.

The colour is real, the superfood story is not

Claim	Reality
Turns blue, shifts purple with lemon	true, pH-sensitive anthocyanin chemistry, not an additive
Caffeine-free, low-calorie	true, it is a flower tisane with no tea leaf
Memory, ageing and fat burning claims	not at cup strength, rests on concentrated-extract lab studies
"Superfood"	a pigment found in many colourful plants, not a treatment

In short: a nice, harmless, caffeine-free, photogenic drink with no demonstrated special powers in cup form, which is an accurate label rather than a criticism. It is a tisane, not tea, an infusion of dried Clitoria ternatea flowers grown across South-East Asia, mild, slightly earthy and woody, so it is often blended with lemongrass, ginger or fruit and used as much for colour as taste. For general use it is low-risk in normal amounts, one of the gentler tisanes, with the usual sensible caution around pregnancy and concentrated extracts, flags rather than alarms.

Reference noted

NHS: Herbal medicines

From the curatorteas · A well made infusion beats a famous shop name. Brew a budget bag with care and it will outdo a premium one made carelessly.