Ingredient

Tea

Green tea, white tea, oolong, black tea and pu-erh all come from one plant, Camellia sinensis. What makes them different is not the variety but how far the picked leaf is allowed to change before heat stops it — and that single decision accounts for nearly everything you taste.

The one thing that separates them

A tea leaf, once picked, starts to change. Enzymes in the leaf react with oxygen, the green fades to copper and brown, and the fresh, grassy compounds turn into the malty, fruity ones. Tea makers call this oxidation, and the whole craft is deciding when to stop it — which is done with heat, either steaming or firing in a pan or a drum.

Stop it immediately and you have green tea. Stop it barely at all, but dry the leaf gently and handle it very little, and you have white tea. Let it go part of the way and you have oolong, which is really a whole family rather than one thing. Let it go all the way and you have black tea. Pu-erh is a different axis again: it is aged, and the change in it is microbial rather than enzymatic.

The five, and how to brew them

Water temperature matters more than steeping time for most of them. These are the ranges most producers suggest; treat them as a starting point and adjust to taste.

Green

Grassy, sometimes savoury, easily made bitter. Water well off the boil — around 70 to 80°C — for one to two minutes.

White

The most delicate. Faintly sweet, hay and melon. Water around 75 to 85°C, and it tolerates a long steep better than green does.

Oolong

Anywhere from green-and-floral to dark-and-toasty depending on how far it was oxidised. Around 85 to 95°C. Good oolong is meant to be re-brewed several times.

Black

Malty, brisk, tannic. Full boiling water, three to five minutes. This is the only one that reliably stands up to milk.

Pu-erh

Earthy, deep, sometimes barnyard. Boiling water. Rinse the leaf with a first short pour and throw that away.

Why tea goes bitter

Bitterness and astringency in tea come mostly from polyphenols the leaf contains, and how much of them ends up in your cup is a matter of extraction rather than of the tea being bad.

• Water too hot pulls them out faster than it pulls out anything pleasant. This is why green tea in boiling water is harsh and the same tea at 75°C is not.
• Steeped too long does the same thing more slowly. Take the leaf out; do not leave it sitting in the pot.
• Too much leaf for the volume concentrates everything, including the parts you did not want.
• Squeezing the bag presses out the most concentrated, most astringent liquid in the whole cup. Lift it out and let it drain.

Tea as a cooking ingredient

Tea is a source of tannin, smoke and bitterness, which are all useful and none of which most kitchens think of reaching for.

• Smoking. A handful of dry tea leaves with rice and sugar in a foil-lined pan makes a stovetop smoker. Tea-smoked duck is the classic; it works on chicken and firm fish too.
• Poaching and braising liquid. Strong black tea in the pot with dried fruit plumps it and adds a tannic backbone that plain water does not.
• Eggs. Tea eggs — hard-boiled, shells cracked, steeped in black tea with soy and spice — take the marbling and the flavour from the tea.
• Cakes and creams. Earl Grey and Lapsang Souchong both infuse into cream or milk readily; strain and use it as the liquid.
• Cured and rubbed. Ground tea in a salt cure or a dry rub brings tannin and a dry, savoury edge.

What is not tea

Rooibos, honeybush, chamomile, peppermint, hibiscus and yerba mate are all infusions and none of them is tea, because none of them comes from Camellia sinensis. This is not pedantry: they behave differently. Most contain no caffeine, most contain far less tannin, and most cannot be over-extracted the way tea can — you can leave chamomile in the pot for ten minutes and it will not turn bitter.

If a recipe tells you to brew something strong and it turns out unpleasant, the first question is which of the two you are actually holding.

Making it well

• Use water just off the boil for black tea, and noticeably cooler — around 80°C — for green and white, which turn bitter above that.
• Give it room. Leaves need to unfurl, so a bag squeezed into a small pot extracts unevenly. A basket infuser or a pot is genuinely better.
• Time it. Over-steeping extracts tannins and makes tea astringent, and this is the commonest fault by a distance.
• Do not squeeze the bag. That is where the harshest tannin comes from.
• Store tea airtight, away from light, heat and anything aromatic. It absorbs smells readily, which is how tea ends up tasting of the spice cupboard.

Common questions