Cold brew tea
Leaf steeped in cold water in the refrigerator for several hours. Low temperature extracts the sweet and savoury compounds readily and the bitter and astringent ones barely at all, producing a cup that is genuinely different rather than simply a chilled version of a hot one.
Also called mizudashi, cold steeping, refrigerator brewing.
How it works
Roughly 1 g of leaf per 100 ml of cold water, sealed and refrigerated for six to twelve hours, then strained. Because extraction is slow and selective, timing is forgiving — an extra two hours changes far less than an extra two minutes would in hot water. Green and white teas benefit most; heavily roasted and dark teas give comparatively little.
Why choose it
It produces sweetness and body from teas that would need careful hot brewing to show either, and it is close to impossible to get wrong. It is also the safe way to make cold tea, because refrigeration keeps the water out of the range where bacteria multiply quickly.
Equipment
- Glass teapot — Borosilicate glass
Tea types it suits
Recorded on the method rather than inferred from the catalogue. A type missing here is not ruled out; it simply has not been written down.
Common problems
- Using hot water first and then chilling, which is iced tea and tastes quite different
- Leaving the leaf in for days rather than hours
- Expecting a roasted or dark tea to give the same result — they need heat to open
Diagnosed problems
Written from the symptom, with the likely causes in order and a question to rule each one out.
- My cold brew tastes like faintly flavoured water — After a night in the fridge the jug is pale and tastes of very little, with none of the sweetness cold brewing is supposed to give.
- My iced tea has gone cloudy — Tea that was clear when hot turns hazy or milky once chilled.
- My matcha will not mix into cold water — Whisked straight into cold water or ice, the powder stays in lumps, floats in rafts on the surface and sinks in clumps to the bottom.
Teas with parameters authored for this method
75 teas have a parameter set written for cold brew tea. The first 40 are shown, in alphabetical order. Each row is transcribed from that tea’s own record.
| Tea | Leaf (g/100 ml) | Water (°C) | Authored infusions | First infusion (s) |
|---|---|---|---|---|
| Alishan oolong | 2–3 | 4–10 | 1 | 43200 |
| Anji Bai Cha | 1.2–2 | 4–10 | 1 | 25200 |
| Argentine black tea | 1–1.5 | 4–10 | 1 | 28800 |
| Asamushi sencha | 1.5–2.5 | 3–8 | 1 | 28800 |
| Bai Hao Yin Zhen (Silver Needle) | 1–2 | 4–10 | 1 | 21600 |
| Bai Mudan | 1–2 | 4–10 | 1 | 21600 |
| Bai Mudan Wang | 1.5–2.5 | 4–10 | 1 | 36000 |
| Bailin Jin Hao | 1.2–2 | 3–8 | 1 | 21600 |
| Baozhong | 1.5–2.5 | 4–10 | 1 | 21600 |
| Ben Shan | 1.5–2.5 | 4–10 | 1 | 43200 |
| Bi Luo Chun | 1.2–2 | 4–10 | 1 | 25200 |
| Ceylon silver tips | 1.5–2.5 | 4–10 | 1 | 25200 |
| Chumushi sencha | 1.5–2.5 | 3–8 | 1 | 28800 |
| Cui Yu | 2–3 | 4–10 | 1 | 43200 |
| Da Yu Ling | 2–3 | 4–10 | 1 | 43200 |
| Darjeeling first flush | 1.2–2 | 4–10 | 1 | 28800 |
| Darjeeling white tea | 1.5–2.5 | 4–10 | 1 | 25200 |
| Dian Hong | 1–2 | 4–10 | 1 | 21600 |
| Dong Pian | 1.5–2.5 | 4–10 | 1 | 21600 |
| Fuding Silver Needle | 1.5–2.5 | 4–10 | 1 | 36000 |
| Fukamushicha | 1.5–2.5 | 3–8 | 1 | 28800 |
| Fushou Shan | 0.8–1.5 | 2–10 | 1 | 28800 |
| GABA oolong | 0.8–1.5 | 2–10 | 1 | 28800 |
| Genmaicha | 2–3 | 3–8 | 1 | 18000 |
| Golden Monkey | 1.2–2 | 4–10 | 1 | 28800 |
| Golden Needle | 1.2–2 | 3–8 | 1 | 21600 |
| Gong Mei | 1.5–2.5 | 4–10 | 1 | 36000 |
| Guricha | 1.5–2.5 | 3–8 | 1 | 28800 |
| Gyokuro | 1–2 | 4–10 | 1 | 21600 |
| High mountain oolong | 1–2 | 4–10 | 1 | 21600 |
| Hojicha | 2–3 | 3–8 | 1 | 18000 |
| Huang Jin Gui | 1.5–2.5 | 4–10 | 1 | 43200 |
| Huangshan Maofeng | 1.2–2 | 4–10 | 1 | 25200 |
| Jasmine dragon pearl | 1.2–2 | 4–10 | 1 | 25200 |
| Jasmine green tea | 1.2–2 | 4–10 | 1 | 25200 |
| Jasmine Silver Needle | 1.5–2.5 | 4–10 | 1 | 36000 |
| Jin Jun Mei | 1.2–2 | 3–8 | 1 | 21600 |
| Jin Xuan | 1–2 | 4–10 | 1 | 21600 |
| Kabusecha | 1–2 | 4–10 | 1 | 21600 |
| Kagoshima sencha | 1.5–2.5 | 3–8 | 1 | 28800 |
Other cold brew methods
Same family, so the approach is close — the vessel, the ratio and the intent still differ.
- Ice steeping (kōridashi) — Ice cubes placed directly on dry leaf and left to melt, with no water added at all. The liquor arrives as the ice goes, drop by drop, and there is very little of it. It is the coldest steeping in ordinary practice and produces the most concentrated sweet extraction of any.
- Sun tea — Tea left to steep in a jar in direct sunlight for several hours. It is a traditional American summer method, and it is the one preparation in this catalogue where TeaHQ recommends a substitute rather than the method itself.
Sources
This page is TeaHQ synthesis. No external source stands behind the description of this method. It is written from common practice as TeaHQ understands it, and the parameters in the table above come from each tea’s own record rather than from this page.
The numbers for this method are held per tea, never on the method itself. Where a tea has no set written for cold brew tea, TeaHQ shows nothing rather than converting its numbers from another style — a scaled ratio and a halved time read as an answer while being one nobody authored.
Written comparisons
Where TeaHQ has set this method against something it is routinely confused with, and argued the differences out in full.
- Cold brew vs flash-chilled iced tea — Two ways to arrive at cold tea that extract differently and taste genuinely unlike each other. Neither is a shortcut to the other.
- Cold brew vs hot brewing — The same leaf in cold water produces a measurably different drink, and not simply a colder one. Temperature decides which compounds come out.
- Ice steeping (kōridashi) vs cold brew — Two cold extractions with different water and different intent. Cold brew adds cold water and waits hours; ice steeping adds no water at all — ice is placed on dry leaf and the liquor arrives drop by drop as it melts.
- Sun tea vs refrigerator cold brew — Both steep tea slowly in water that was never boiled, and they are often treated as the same idea with different equipment. The temperature at which each one sits is what separates them, and it separates them on flavour as well as on the reason public-health guidance exists.