Gongfu BrewingGuide
Cold Brew Tea: The Easiest Way to Make Iced Tea That's Almost Never Bitter
To cold brew tea, put loose leaf in cold water and leave it in the fridge for 8–12 hours, then strain. A good starting ratio is about 2 teaspoons of leaf per litre (roughly 5–10 g, depending on the tea). Cold water pulls out sweetness and aroma but very little bitterness, so the result is smooth, sweet and almost impossible to ruin. The best teas for it are Taiwanese high-mountain oolong, Oriental Beauty, white tea and red tea. Green teas work too, but they can turn slightly bitter, so keep their time shorter.
I'll admit I came to cold brew late, and a bit snobbishly. Iced tea, to me, meant sugary bottles from the supermarket. Then a July heatwave hit Slovenia, and gongfu at 35 °C in the afternoon stopped being fun. On a whim I dropped some leftover Taiwanese oolong into a bottle of water and forgot it in the fridge overnight. The next morning I had a litre of the sweetest, most floral tea I'd tasted all summer. No bitterness, no effort.
Since then there's a bottle of cold brew in my fridge from June to September. This is the Taiwanese summer method, and it's the easiest good tea you'll ever make.
How to cold brew tea#
- Pick a clean bottle or jar, about 1 litre, glass if possible.
- Add the leaf. About 2 teaspoons per litre to start. Rolled oolongs are dense, so 5–6 g is plenty; fluffy white tea needs more by volume, closer to 8–10 g.
- Fill with cold, fresh, filtered water. Hard water dulls cold brew just as it dulls hot tea: see water for tea.
- Close and refrigerate for 8–12 hours. Overnight is perfect.
- Strain through a fine sieve into a clean bottle. Don't leave the leaves in for days.
- Drink within about a day, and keep it in the fridge.
That's it. Taste it after 8 hours; if you'd like it stronger, leave it a bit longer or use more leaf next time.
Which teas work best#
| Tea | Amount per litre | Time in fridge | What you get |
|---|---|---|---|
| Taiwanese high-mountain oolong | 5–6 g | 8–12 h | Floral, creamy, pear and lilac; my favourite |
| Oriental Beauty | 6–8 g | 8–12 h | Honey and muscat grape; tastes like a natural fruit drink |
| White tea (Silver Needle, Bai Mu Dan) | 8–10 g | 8–12 h | Delicate, sweet, hay and melon |
| Red tea (Dian Hong, Keemun) | 5–6 g | 8–12 h | Malty, sweet, like a very smooth iced tea |
| Jasmine tea | 5 g | 6–8 h | Floral and refreshing |
| Green tea (Longjing, Mao Feng) | 4–5 g | 4–6 h | Fresh and green; can turn slightly bitter if left too long |
| Roasted oolong | 6 g | 8–12 h | Toasty and smooth, like a light cold coffee |
Teas I'd skip#
- Broken leaf and fannings. They extract too fast and cloud the brew.
- Heavily smoked teas. The smoke gets stronger and flatter when cold.
- Young sheng pu-erh. It can work, but cold brew tends to bring out its grassy side more than its sweetness.
- Low-grade green tea. Bitterness and a stale, hay-like taste show up clearly when cold.
My summer routine#
Here's my standard July setup: a 1-litre glass bottle, 6 g of Taiwanese high-mountain oolong, cold filtered water, into the fridge at around 10 pm.
7 am (9 hours). Pale gold, a little cloudy at first. Lilac and fresh cream on the nose, sweet and silky in the mouth. No bitterness at all. I strain it into a clean bottle.
Noon. Still excellent. Colder and even sweeter, with a pear-like freshness.
Evening. Slightly softer, still good. I finish it before bed.
The leaves still have life in them after straining. I often brew them once more gongfu-style, hot, the next evening, and they give three or four surprisingly good steeps.
Why cold brew is almost never bitter#
Bitterness and astringency in tea come mainly from caffeine and certain polyphenols, which dissolve much faster in hot water. Sweet, aromatic compounds and amino acids like L-theanine come out more readily even in cold water. So cold brewing shifts the balance towards sweetness and aroma. That's why even teas that are easy to over-brew hot, like green tea, become forgiving when cold. Cold-brewed tea is also generally a little gentler, though the exact caffeine content depends on the leaf, the amount and the time.
Cold brew vs hot brew poured over ice#
| Cold brew | Hot brew over ice (flash chilling) | |
|---|---|---|
| Time | 8–12 hours | Minutes |
| Taste | Sweet, smooth, very little bitterness | Brighter, more aromatic, more body |
| Risk of bitterness | Very low | Moderate; brew strong but short |
| Best for | Planning ahead, a bottle in the fridge | When you want iced tea now |
For flash chilling, brew the tea double strength with short steeps and pour it straight over a glass full of ice.
Food safety#
Cold brew is made without boiling water, so treat it like a fresh drink: use clean bottles, clean water and good leaf, keep it in the fridge the whole time, and drink it within about a day. If it smells sour or looks slimy, throw it away.
Myths about cold brew tea#
"You need special cold-brew tea bags." Any good whole-leaf tea works, often better than bags.
"Cold brew tea is weak." Not if you use enough leaf and time. It's lighter in bitterness, not in flavour.
"You can leave it in the fridge for a week." Strain it after about 12 hours and drink it within a day for the best taste and safety.
"Only green tea is good cold." In my experience, oolong, white and red teas make better cold brew than most green teas.
My honest take#
If you only try one thing from this page, make it a litre of cold-brewed Taiwanese high-mountain oolong. It's the easiest way to show someone how good tea can taste, and it turned a hot Slovenian summer into one of my best tea seasons. More on the tea itself in my Taiwanese oolong guide.
The bottom line#
About 2 teaspoons of whole-leaf tea per litre, cold filtered water, 8–12 hours in the fridge, strain and drink within a day. Choose oolong, white or red tea, keep green tea times short, and you'll never make a bitter iced tea again.
Read next: where to buy Chinese tea online.
Questions people ask
How do you cold brew tea?
Put loose leaf in cold water, refrigerate for 8–12 hours, then strain. About 2 teaspoons per litre is a good start.
How long should you cold brew tea?
Most teas: 8–12 hours. Green tea: 4–6 hours, or it can turn slightly bitter.
What's the best tea to cold brew?
Taiwanese high-mountain oolong, Oriental Beauty, white tea and red tea.
Is cold brew tea less bitter?
Yes. Cold water extracts far less of the compounds that make tea bitter, so it tastes sweeter and smoother.
Does cold brew tea have less caffeine?
It's usually a bit gentler, but the amount depends on the tea, the quantity of leaf and the steeping time.
How long does cold brew tea last?
Best within about a day, kept in the fridge. Strain the leaves out after 8–12 hours.