The short answer: cold brew tea is tea steeped in cold water in the fridge instead of hot water on the stove. Put 8 to 10 g of loose tea, or 4 to 5 tea bags, in 1 litre of cold water. Steep it in the fridge for 6 to 8 hours for green tea or 8 to 12 hours for black tea. Strain it and drink it within 3 to 4 days.
Hot water pulls flavour out of tea in minutes, and the bitter, drying notes come with it. Cold brew tea takes the long way. You fill a jug before bed and pour a smooth, clear iced tea in the morning. No kettle, no ice to melt a hot brew, and very little to go wrong. Here is the ratio, the steeping time for each kind of tea, and how to keep it.
| At a glance | |
|---|---|
| Ratio | 8 to 10 g loose tea, or 4 to 5 bags, per 1 litre cold water |
| Time | 6 to 12 hours in the fridge, by tea type |
| Makes | 1 litre (about 4 cups) |
| Keeps | 3 to 4 days in the fridge, after straining |
What you need
- 8 to 10 g (about 4 teaspoons) loose tea, or 4 to 5 tea bags
- 1 litre (4 cups) cold filtered or tap water
- A clean jug or large jar with a lid
- A fine sieve, if you use loose tea
- Optional: lemon slices, mint sprigs, a little syrup to sweeten
Loose leaf gives more flavour than most bags because the leaves are bigger and have room to open. Bags are tidier. Both work.
How to make cold brew tea
- Measure. Put the tea in the jug. Use the top of the range for a stronger glass, the bottom for a lighter one.
- Pour. Pour in 1 litre of cold water. Stir once so every leaf gets wet.
- Cover. Put on the lid and place the jug in the fridge straight away.
- Steep. Leave it for the time in the table below. Overnight is right for most teas.
- Strain. Pour it through a sieve, or lift out the bags. Do not squeeze them. Squeezing pushes bitter liquid back in.
- Serve. Pour over ice. Keep the rest covered in the fridge.
How long to steep each tea
| Tea | Time in the fridge | What you get |
|---|---|---|
| Green or white | 6 to 8 hours | Sweet, grassy, very pale |
| Black | 8 to 12 hours | Malty, amber, no bite |
| Oolong | 8 to 12 hours | Floral, honey colour |
| Herbal, fruit or rooibos | Do not cold brew | Brew with boiling water, then chill |
Taste it at the short end of the range. If it is weak, give it two more hours. Cold brew forgives you. A few extra hours makes it stronger, not harsh, because the cold water pulls out far less of the bitter side of the leaf.
Why cold brew tea tastes smoother
Heat brings out the tannic, bitter flavours in tea. That is the dry feeling on your tongue after a long hot steep. Cold water works slowly. Over a night it takes the sweet and floral notes and leaves most of the bitter ones in the leaf. That is why a green tea that turns harsh in a hot pot can taste soft and sweet as cold brew.
Herbal, fruit and rooibos teas are the exception. Dried herbs and fruit can carry germs that only boiling water reliably kills. Germany's food-safety institute, the BfR, says to make them with water at a rolling boil and steep them for at least 5 minutes. For an iced herbal tea, brew it hot that way, let it cool, then chill it in the fridge.
Keep it in the fridge, not in the sun
Steep cold brew tea in the fridge from the first minute. Do not leave a jug on the counter or in a sunny window. Warm water and time give bacteria a good place to grow. In 1996 the US CDC warned that sun tea carries a higher risk than tea brewed with hot water for that reason. Your fridge keeps the water cold the whole time, which is the point.
- Use a clean jug and clean hands.
- Strain once it has steeped. Leaves left in for days start to taste stewed.
- Drink it within 3 to 4 days of straining.
- Throw it out if it turns cloudy, slimy or sour.
How to sweeten cold brew tea
Sugar sinks to the bottom of cold tea and stays there as grit. Use a liquid sweetener instead. Stir in 1 to 2 tablespoons of simple syrup per glass, then taste. For a warm, spicy glass, use ginger syrup with black tea and a slice of lemon. Honey works too, but it stiffens in the cold, so loosen it first with a spoon of warm water. Do not give honey to babies under 12 months.
Five ways to flavour it
- Lemon: add 3 or 4 thin lemon slices after straining, not during the steep, so the pith does not turn it bitter.
- Mint: add a few fresh mint leaves to each glass of green tea as you serve it.
- Peach: add half a sliced ripe peach to black tea after straining.
- Berries: crush a few raspberries into the glass with the ice.
- Half and half: mix it 1 to 1 with lemonade or sparkling water.
If you already make cold brew coffee, it is the same idea. Cold water, time, the fridge, then strain.
Common mistakes
- Weak tea: not enough leaf. Go to 10 g per litre before you add time.
- Grainy bottom: sugar added cold. Use a syrup.
- Bitter edge: squeezed bags, or lemon steeped with the leaves.
- Stale taste: the leaves stayed in for two days. Strain once it is ready.
Questions
How long does cold brew tea take?
Steep green or white tea in the fridge for 6 to 8 hours. Steep black tea and oolong for 8 to 12 hours. Herbal, fruit and rooibos teas are not cold brewed: make them with boiling water, then chill.
What is the ratio for cold brew tea?
Use 8 to 10 g of loose tea, about 4 teaspoons, or 4 to 5 tea bags for every litre of cold water. Use more tea, not more time, if you want it stronger.
How long does cold brew tea last in the fridge?
Keep it covered in the fridge and drink it within 3 to 4 days after straining. Throw it out if it turns cloudy, slimy or sour.
Can I cold brew tea on the counter?
No. Steep it in the fridge. Tea left in water at room temperature or in the sun gives bacteria time to grow.
Can I use tea bags for cold brew tea?
Yes. Use 4 to 5 standard bags per litre of cold water and lift them out without squeezing when the tea is ready.
