Why Does Tea Taste Bitter? And the Rules for Brewing It Right

Tea is the simplest drink in the world and the one most often made wrong. The bitterness many people accept as normal is really a brewing mistake.

Tannins: where the bitterness comes from

Tea leaves contain compounds called polyphenols — among them tannins, which are responsible for the astringent, bitter taste.

Tannins are released slowly compared with the aromatic compounds and caffeine.

In other words: the first two minutes bring out the flavour and aroma, and the minutes after that bring out the tannins and the bitterness.

And the hotter the water, the faster the tannins are extracted. That is the rule that explains everything.

Temperature and time chart

• Black tea: 95°C · 3–4 minutes.
• Green tea: 75–80°C · 1.5–2 minutes.
• White tea: 75°C · 2–3 minutes.
• Oolong: 85–90°C · 3 minutes.
• Herbal teas (hibiscus, chamomile, mint): 100°C · 5–7 minutes (they have no tea tannins, so they don’t turn bitter).

How to hit 95°C without a thermometer: boil the water, turn off the heat and wait 30 seconds. For green tea, wait 3–4 minutes, or add a quarter of a cup of cold water.

Mistake one: boiling water on green tea

This is the most common mistake of all.

Green tea leaves are unoxidised and delicate, and boiling water literally scorches them — the result is an unpleasantly bitter, astringent taste.

Plenty of people say ‘I don’t like green tea’ when in fact they have never had green tea brewed properly.

Mistake two: steeping too long

Leaving the tea in the cup ‘so it gets strong’ gives you bitterness, not strength.

If you want it strong: use more leaf, not a longer steep.

The rule: take out the bag or infuser once the time is up — don’t leave it in the cup.

Mistake three: boiling tea on the hob

Boiling tea with the water on the hob extracts all of the tannins — that is what gives the dark colour and astringent taste.

In Saidi tea from Upper Egypt this is actually deliberate (more on that below), but it is not the right method for ordinary tea.

Koshari tea vs Saidi tea

These are two completely different Egyptian schools:

Koshari tea: the water is boiled, the tea goes into the cup or teapot, and the water is poured over it and left for 3–5 minutes. It tastes gentler and is lighter in colour. This is the method closest to correct.

Saidi, or Upper Egyptian, tea (dammas): the tea is boiled with the water on the hob for 3–5 minutes. It is very strong and astringent, very dark, and has far more caffeine.

Saidi tea is a deep-rooted tradition with its own devotees — but the bitterness in it is intentional, not a flaw.

Water quality

A cup of tea is 99% water, so its quality really matters.

• Filtered water is better than chlorinated tap water.
• Fresh water — water that has been boiled before has lost its oxygen, and the tea comes out flat.
• Not distilled water — minerals are needed to extract the flavour.

Amount and ratio

2–3 g of tea (a teaspoon) per 200 ml of water.

Loose tea is better than bags — the leaf in bags is finely broken, so it releases tannins faster and turns bitter more easily.

If you use bags, cut the time by 30 seconds.

Why milk changes the taste

The casein protein in milk binds to tannins and softens the sense of astringency and bitterness.

That is why tea with milk tastes smoother — and also why milk goes into strong tea in particular.

The milk-first or tea-first debate does have a real basis: putting the milk in first stops its protein curdling from the heat shock, so the taste is smoother.

Storing tea

• An airtight, opaque tin — light and air oxidise the leaves.
• Away from strong smells — tea absorbs them astonishingly fast.
• Not in the fridge — the moisture ruins it.
• Shelf life: two years for black, and one year for green (it loses its flavour faster).

Caffeine: the numbers

• Black tea (200 ml): 40–70 mg.
• Green tea: 25–45 mg.
• White tea: 15–30 mg.
• Filter coffee (200 ml): 95–140 mg.

Longer steeping means more caffeine — so a light tea brewed briefly has less caffeine for a reason, not by chance.

Theanine in tea moderates the effect of caffeine, which is why tea gives a calmer lift than coffee.

Mint and herbal teas

Herbs don’t have tea’s tannins, so they don’t turn bitter however long they steep — and that changes the rules.

Chamomile, hibiscus, aniseed and cinnamon can all take boiling water and a steep of 5–7 minutes or more.

Fresh mint is the exception: its leaves are delicate, and boiling water blackens them and draws out a bitter, grassy taste. Add it at the end, after you take the water off the heat.

Moroccan mint tea is made differently — gunpowder green tea with mint and plenty of sugar, poured from a height to make a froth.

After brewing: settling and storage

Brewed tea changes quickly once it cools — oxidation gives it a metallic taste and a dark, cloudy colour.

If you are making iced tea, make it as a cold-brewed concentrate: tea leaves in cold water in the fridge for 6 to 12 hours. This method extracts the flavour with almost no tannins, and the result is a sweet, smooth tea with no bitterness at all.

Summary

Black tea at 95°C for 3–4 minutes, green at 80°C for two minutes. Take the leaves out when the time is up, add more leaf rather than more time if you want it strong, and use fresh, filtered water. Bitterness isn’t strength — it is excess tannin.