Brewing Is Extraction

Hot water pulls compounds out of the leaf, and they do not all come out at the same rate.

Aromatics and sweetness come out first. Caffeine, which is bitter, comes out fast. Tannins, which are astringent and drying, come out slowly and keep coming.

That sequence explains everything about brewing. A short steep in cooler water gives you the sweet and aromatic end. A long steep in very hot water pulls everything, including a great deal you did not want. Bitterness in tea is nearly always over-extraction, not bad tea.

Temperature

The variable that makes the biggest difference and the one most often ignored, because most people own a kettle with one setting.

Rough starting points:

Green tea: 70 to 80C. Japanese greens at the lower end, some as low as 60 for gyokuro. Boiling water on green tea produces a bitter, spinach-like cup, and this single mistake is responsible for most of the people who believe they dislike green tea.

White tea: 75 to 85C.

Oolong: 85 to 95C, lighter green oolongs lower, roasted ones higher.

Black tea: 90 to 100C. Full boiling is correct for most, though delicate Darjeelings prefer around 90.

Pu-erh: 95 to 100C.

Herbal infusions: 100C, always.

If your kettle has no temperature control, there are two workable methods. Boil and wait - freshly boiled water in a room-temperature cup drops roughly 10C in the first minute, and continues falling more slowly, so three to four minutes of standing gets you to green tea temperature. Or add cold water: about one part cold to four parts boiling lands near 80C.

A thermometer costs very little and removes the guesswork entirely. A variable-temperature kettle is the single most worthwhile piece of tea equipment there is.

Leaf Quantity

The standard reference is 2 to 3 grams of leaf per 200ml of water - roughly a rounded teaspoon, though this varies enormously by leaf shape.

This is where volume measures mislead. A teaspoon of tightly rolled gunpowder green weighs perhaps three times a teaspoon of fluffy White Peony. A cheap kitchen scale solves this permanently, and it is the fastest route to consistent tea.

Adjustments worth knowing: white teas want more leaf than seems reasonable, often 4 to 5g. Rolled oolongs expand dramatically and need room.

If your tea is weak, add leaf. Do not extend the steeping time. Longer steeping extracts more tannin and more bitterness; more leaf extracts more of everything in the same proportion. This is the single most useful adjustment principle in brewing.

Time

With correct temperature and quantity, the times are short:

Green: 1 to 3 minutes, Japanese greens often 60 to 90 seconds.

White: 3 to 5 minutes.

Oolong (western style): 2 to 3 minutes.

Black: 3 to 5 minutes. Beyond five, most black teas turn astringent.

Pu-erh: 2 to 4 minutes, ripe pu-erh often rinsed briefly first.

Herbals: 5 to 10 minutes, and they cannot really be over-steeped.

Remove the leaf when the time is up. Leaving leaf sitting in the pot means the tea continues extracting and the last cup is bitter - which is precisely what happens with those infuser baskets that sit in the mug while you drink. Take the basket out and rest it on a saucer.

Water

Tea is over ninety-nine percent water, which people acknowledge and then ignore.

Very hard water - high in calcium and magnesium - dulls and flattens tea, mutes aromatics, and creates the scummy film on the surface of a cup and the limescale in your kettle. This is the reason the same tea tastes different in different cities.

Very soft or distilled water is also wrong: some mineral content is needed to extract properly, and distilled water makes flat, hollow tea.

Moderately soft filtered water is the target. A simple jug filter makes a noticeable difference in a hard water area and costs almost nothing.

Two habits worth having: use freshly drawn water, because water that has been sitting or reboiled has lost dissolved oxygen and makes tea taste flat; and never brew with hot water from the tap, which sits in a tank and carries more dissolved metals.

Diagnosing a Bad Cup

Bitter and harsh: water too hot, or steeped too long. Drop the temperature by 10C first.

Astringent and drying: over-steeped. Cut the time.

Weak and watery: not enough leaf. Add leaf; do not add time.

Flat and dull: water quality, stale leaf, or reboiled water.

Tastes of nothing much despite following the instructions: the leaf is probably old. Tea does not spoil dangerously, but it fades, and most of it fades faster than the packaging implies.

Change one variable at a time, and brew the same tea twice in a row with only that one thing different. This is the whole method, and two afternoons of it will teach you more than any amount of reading.

Repeated Steepings

Western brewing uses little leaf, a lot of water, and one long steep. Gongfu brewing - the Chinese method - inverts it: a great deal of leaf in a small vessel, water for a few seconds at a time, and eight or more infusions from the same leaf.

You do not need special equipment to try it. Use roughly 5g of oolong in a small teapot or even a mug with a lid, fill with 100ml of water at 90C, and pour off after 20 seconds. Then again, adding five seconds each time.

The tea changes with each infusion, and this is the most direct way to understand what extraction actually is.