Mint Turns Bitter the Moment You Boil It

This looks at mint leaves in chai from the practical end — what holds up once conditions stop being ideal.

What happens in a boiling pan

The cooling sensation in mint comes from menthol, which is a highly volatile compound. At a rolling boil it leaves with the steam within a minute, taking the entire point of the herb with it. The leaf itself stays in the pan and keeps releasing tannin and chlorophyll into the liquid.

The result is a cup that tastes green, grassy and faintly bitter without any cooling character at all. That flavour is what most people mean when they say they do not like mint in tea.

The off-heat method

Finish the chai completely, then take the pan off the flame and let it stop bubbling. Add eight to ten torn mint leaves, cover the pan and leave it for three or four minutes.

Straining at that point gives you the menthol and very little of the bitterness. A lid is essential rather than optional, because an open pan loses the aromatics almost as fast as boiling does. Tearing rather than chopping avoids bruising the leaf against a board and releasing the green notes early.

Spearmint against peppermint

Most fresh mint sold in South Asian and Middle Eastern shops is spearmint, which is gentler and sweeter. Peppermint carries far more menthol and is considerably more aggressive in a small glass. Spearmint suits milk chai, where its softness sits alongside the dairy without fighting it.

Peppermint belongs in black tea, where there is nothing for it to clash with. Using peppermint at spearmint quantities is the second commonest way a mint cup goes wrong.

Mint with milk

Mint and milk is not a natural pairing, and a great many mint teas around the world are served black for that reason. The cooling character reads as slightly odd against a fatty, warm mouthfeel. If you want both, keep the milk ratio low and the mint dose modest rather than doubling either.

Mint and ginger together work better in milk than mint alone, because the ginger bridges the gap.

Moroccan-style mint tea, which uses green tea and no milk at all, is a different drink built on the same herb.

Dried mint

Dried mint keeps its menthol reasonably well and is a genuinely useful cupboard item. Use roughly a third of the volume you would use fresh, since drying concentrates it considerably.

The ratio does the work here: it still needs the off-heat method, because the menthol is just as volatile once rehydrated. Store it whole rather than crushed, and crush it between your palms as it goes into the pan. Mint that has faded to a grey-green with no smell should be thrown out rather than used in larger quantities.

Spices fade at their own pace, and a year-old tin needs more of everything.

Growing and picking it

Mint grows aggressively and is best kept in a pot unless you want it across an entire garden. Pick young leaves from the top of the stem, since older lower leaves are tougher and more bitter. Leaves picked just before flowering carry the most menthol, and flowering reduces it noticeably.

The ratio does the work here: rinse and dry the leaves before use, because water clinging to them dilutes the small volume you are infusing. A single plant on a windowsill supplies more mint than most households can get through.

The takeaway

Mint goes in after the flame goes off, and the lid goes on straight after the mint.

A good glass is mostly fresh spice and the patience to let it boil twice.