Cold brew tea: types, steeping time and what to watch out for
Cold brew tea is not brewed hot but made with cold water and left to steep for many hours in the fridge. The result tastes milder, less harsh and often surprisingly sweet – without any sugar. The method is as simple as it gets and even works directly in your water bottle. There is one important restriction, however, that many people do not know about: not every tea should be steeped cold. In this article you will learn which kinds are suitable, how much tea and time you need and what to watch out for in terms of hygiene.
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What is cold brew tea?
With the classic method you pour hot water over tea leaves and let them steep for a few minutes. With cold brewing you use cold water instead and give the tea much more time, usually several hours in the fridge.
Because the temperature is low, the compounds dissolve more slowly and differently. Bitter substances and tannins pass into the water much more strongly with a hot infusion. Cold-brewed tea therefore usually tastes gentler and more rounded. Green teas in particular, which quickly turn bitter when brewed hot, often show a whole new, fresh side.
The difference from iced tea: iced tea is brewed hot and then cooled. Cold brewing, by contrast, never involves hot water at any stage.
Which teas are suitable for cold brew?
“True” teas are best suited for cold brewing, i.e. green tea, black tea, white tea and oolong. They are processed and dried during production and can easily be steeped cold.
Important: do not cold-brew herbal and fruit teas
Herbal and fruit teas are a completely different matter. The German consumer advice centre (Verbraucherzentrale) advises against steeping them with cold water. Herbs and fruit are only dried after harvest and not heated. They can therefore contain germs such as bacteria, yeasts or moulds, which are only killed by boiling water. For babies, children and people with pre-existing conditions this can be risky.
The recommendation instead: pour bubbling boiling water over herbal or fruit tea, let it steep for at least five minutes and then let it cool. The exception is special cold brew blends sold in shops. According to the German health magazine Apotheken Umschau, they are treated with hot steam to reduce the germ count. Look for an explicit note on the packaging that the tea is suitable for cold brewing.
| Type of tea | Steep cold? | Taste as cold brew |
|---|---|---|
| Green tea | Yes | Fresh, grassy, hardly bitter |
| Black tea | Yes | Mild, malty, less harsh |
| White tea | Yes | Very delicate, slightly floral |
| Oolong | Yes | Rounded, often slightly fruity |
| Herbal tea, fruit tea | No, brew hot only | Exception: explicitly labelled as a cold brew blend |
Making cold brew tea: basic recipe
To start with, a simple rule of thumb is enough. A common guide is about one heaped teaspoon of loose tea or one tea bag per 250 ml of water, i.e. around four teaspoons per litre. Because less flavour is extracted when cold, you can use a little more than for a hot infusion.
- Clean the container: Rinse the carafe, glass bottle or water bottle with hot water.
- Add the tea: Put loose tea into a tea filter or infuser, or simply drop in tea bags.
- Top up with cold water: Use fresh, cold tap water.
- Steep in the fridge: Green and white tea for about 6 to 8 hours, black tea and oolong for 8 to 12 hours. Taste in between and take the tea out when you like it.
- Remove the tea: Take out the filter or bags, strain loose tea. Done.
The most practical way is to start the cold brew in the evening. The next morning it is ready and can come straight along.
Ideas for refining it
- Green tea with a few slices of cucumber or lime
- Black tea with a slice of lemon and a little mint
- White tea with a few fresh raspberries, just before drinking
- Oolong on its own – it usually needs nothing added
Wash fresh ingredients such as fruit and herbs thoroughly and add them only just before drinking.
Common mistakes
- Too little tea: Less aroma passes into the water when cold. If you use the same amount as for a hot infusion, the result is often thin.
- Not steeped long enough: After an hour the tea usually still tastes of almost nothing. Plan for it to steep overnight.
- Tea left in too long: After more than a day in the water, even cold-brewed tea can turn harsh.
- On the worktop instead of in the fridge: At room temperature, germs have an easier time.
Cold brew tea in your water bottle
You can steep the tea directly in the bottle you will later take with you. A tea bag or a slim tea filter that fits through the opening goes in, cold water on top, lid on and into the fridge. In the morning, take the tea out – otherwise it keeps steeping all day and gets stronger.
An insulated bottle then keeps the cold brew pleasantly cool on the go. According to the manufacturer, our IZY bottles keep drinks cold for up to 24 hours, are taste-neutral and have a leak-proof screw cap.
- IZY Bottles Van Gogh Flowers thermos bottle – 500 ml: double-walled, rust-free stainless steel, BPA-free, no condensation on the outside.
- IZY x Pip Studio “La Dolce Vita” thermos bottle – 500 ml: playful pattern, same insulation performance according to the manufacturer, in a round gift tin.
You will find all bottles in our IZY collection. After finishing, rinse the bottle and clean it by hand with warm water and mild washing-up liquid. According to the manufacturer, the IZY bottles do not go in the dishwasher.
Shelf life, hygiene and caffeine
A cold brew is never heated. That makes clean work all the more important:
- Only use clean containers and fresh water.
- Always steep in the fridge, not at room temperature.
- Drink the finished tea within about one to two days.
- If it smells or tastes unusual, pour it away.
Cold-brewed green, black or white tea also contains caffeine. So it is not the right choice for children. If you have health questions, for example during pregnancy, it is best to talk to your doctor.
And cold-brewed coffee?
You may know the principle from coffee: coarsely ground coffee steeps for many hours in cold water and is then filtered. The result is a mild coffee with little acidity. The method is related, but the quantities and steeping times are quite different.
More tips on keeping cold drinks cool for as long as possible on hot days can be found in the article Water bottle in summer.
Related reading: Making your own iced tea: basic recipe, variations, less sugar · Tea in a thermos bottle: how it stays hot without turning bitter · Infused water recipes: 8 combinations for water with flavour
Conclusion
Cold brew tea is a simple method for mild, refreshing tea without sugar. Steep green, black, white tea or oolong in cold water and leave it in the fridge for 6 to 12 hours depending on the type. Herbal and fruit teas, on the other hand, should always be brewed with boiling water, unless they are explicitly labelled for cold brewing. Use clean containers, drink the tea within one to two days and take it along cool in an insulated bottle.
Frequently asked questions
How long does cold brew tea need to steep?
Green and white tea about 6 to 8 hours, black tea and oolong about 8 to 12 hours in the fridge. Taste in between and take the tea out when you like it.
Can I cold-brew any tea?
No. According to the Verbraucherzentrale, you should brew herbal and fruit teas with boiling water because they can contain germs. The exception is blends explicitly labelled for cold brewing.
How long does cold brew tea keep?
About one to two days in the fridge. If it smells or tastes unusual, pour it away.
Does cold brew tea contain caffeine?
Yes, if you use green, black, white tea or oolong. It is therefore not suitable for children.
Can I cold-brew the tea directly in my water bottle?
Yes, with a tea bag or a tea filter that fits through the opening. Take the tea out before you head off so that it does not keep steeping.
Personally written by Martin – founder of BeachAndSteam and sauna operator at Lake Kulkwitz for more than 18 years.