How to Make Cold Brew Tea: Ratio and Timing Guide

Cold brew tea is made by placing loose tea leaves in a container with cold drinking water and leaving it in the fridge for 8–12 hours, then straining. Using roughly 10–15 grams of tea per litre is a good starting point. The result is a smooth, gently sweet drink with low bitterness; once prepared, keep it refrigerated and consume within 24–48 hours for best safety.

What Is Cold Brew Tea and How Does It Differ from Hot Brewing?

In hot water, the aroma compounds, caffeine and tannins in tea leaves dissolve within minutes. In cold water this process is much slower, which is why cold brewing is measured in hours rather than minutes. The slow extraction means fewer of the tannins responsible for astringent, bitter notes are released, producing a smoother cup.

Cold brew tea is not the same as hot-brewed tea that has been cooled down. Hot-brewed tea can turn cloudy as it cools and its bitterness may become more pronounced. Cold brew, by contrast, generally stays clear. It is often thought that less caffeine is extracted during cold brewing, but the amount varies with the quantity of tea and steeping time — if you are sensitive to caffeine, do not treat this as a caffeine-free option.

Ingredients and Ratio

You don't need any special equipment for cold brew. A clean glass jug or jar from your kitchen will do the job.

• Loose tea: Roughly 10–15 g per litre of water (approximately 4–6 teaspoons, depending on leaf size).
• Water: Drinking water or filtered water. Chlorinated tap water will noticeably spoil the flavour.
• Container: A glass jug or jar with a lid, thoroughly washed and dried.
• Strainer: A fine-mesh tea strainer; for teas with a high dust content a paper filter can also be used.

If you want a stronger flavour, increase the amount of tea rather than extending the time. Steeping for too long tends to increase astringency rather than depth of flavour.

Cold Brewing Step by Step

1. Prepare the container: Wash the jug with hot water and detergent, rinse thoroughly and dry.
2. Add the tea: Place your measured loose tea directly into the container or into a cloth/muslin brew bag.
3. Add the water: Pour cold drinking water over the tea and stir gently with a spoon so all the leaves are wetted.
4. Seal and refrigerate: Brewing must take place in the fridge — do not leave it at room temperature for hours.
5. Wait: For black tea, 8–12 hours is typical; green tea usually needs less time.
6. Strain: Once the time is up, separate the leaves. If left in, the tea will continue to grow more astringent.
7. Serve: Add ice, a slice of lemon or a few mint leaves as you like.

A practical approach: prepare it before bed, refrigerate overnight and strain in the morning. You'll have a cool drink ready for the whole day. Note the steeping time on your first try; next time, if the flavour was too mild increase the tea slightly, or if it was too astringent shorten the time. After two or three attempts you'll find your ideal ratio.

Which Tea Is Suitable for Cold Brewing?

Many teas can be cold brewed, but not every tea gives the same result. The table below offers a starting point — adjust the time and quantity to suit your own palate.

Tea type	Suggested time (in fridge)	Amount per litre	Flavour character
Black tea (loose leaf)	8–12 hours	10–15 g	Smooth, full-bodied, gently sweet
Green tea	6–8 hours	8–12 g	Fresh, grassy, light
Herbal teas	8–12 hours	Varies by product	Aromatic, caffeine-free options

Large-leaf, well-twisted black teas tend to give a balanced cold brew. Mayıs black tea, produced from the first flush leaves in Rize, has a naturally smooth character that lends itself well to cold brewing. If you'd like to try green tea, Burgulu green tea comes in a small pack that's handy for experimenting. If you're curious about how black and green tea differ in production, have a look at our article on the difference between black tea and green tea.

Hygiene and Storage: The Most Overlooked Part

Because the water is never boiled, cold brewing lacks the heat-treatment advantage of hot brewing. Cleanliness and keeping the cold chain intact are therefore more important. Experts recommend the following rules for cold-brewed drinks:

• Brew in the fridge, not at room temperature.
• Use a clean, lidded and preferably glass container; avoid cracked plastic or containers with scratched inner surfaces.
• Use drinking water; do not cold brew with water of uncertain origin. Our article on which water to use for tea offers guidance.
• After straining, store in the fridge and consume within 24–48 hours.
• If the tea smells sour, has foam or sediment on the surface, or tastes off, discard it.
• Do not leave a poured glass sitting out for a long time, and do not pour leftovers back into the jug.

If you want to add lemon, fruit slices or honey, add them to the glass at serving time rather than during brewing. Fruit pieces left in the jug can shorten the drink's shelf life.

Common Mistakes

• Brewing in the sun: So-called "sun tea" involves long steeping in a warm environment and is not recommended for hygiene reasons.
• Over-steeping: Tea left for 24 hours usually turns bitter; for a stronger brew, increase the amount of tea instead.
• Using stale tea: Because cold brewing produces a softer flavour, the freshness of the tea becomes more noticeable. We explain how to store your tea properly in our article on tea shelf life and storage.
• Trying to dissolve sugar in cold tea: Sugar dissolves poorly in cold water; if you want to sweeten your tea, dissolve a small amount in a little hot water first, then add it.

Frequently Asked Questions

How long should cold brew tea steep?

For black tea, 8–12 hours in the fridge is generally enough; for green tea, 6–8 hours. Steeping longer usually adds astringency rather than depth of flavour.

Can cold brew tea be made at room temperature?

It is not recommended. Since the water is not boiled, brewing in the fridge and keeping the tea in the cold chain is safer from a hygiene standpoint.

How long does cold brew tea keep?

Once strained, cold brew tea is best stored in the fridge and consumed within 24–48 hours. Do not drink tea whose smell or appearance has changed.

Does cold brew tea contain less caffeine?

Because caffeine dissolves more slowly in cold water, less caffeine is thought to be extracted than with hot brewing in most cases. However, the amount varies with the tea used and steeping time — it cannot be considered caffeine-free.

Which tea should I use for cold brewing?

Loose-leaf black tea, green tea and herbal teas all work well. Fresh, large-leaf teas tend to give a more balanced, smoother result.

A Final Word for a Cool Glass of Tea

Cold brewing is an easy way to enjoy tea even on hot days: the right ratio, patient waiting in the fridge and a clean jug are all you need. If you're also curious about the finer points of hot brewing, take a look at our guide on how to brew Berberoğlu tea. In the summer months, keeping a jug of cold brew tea ready in the fridge offers a simple and enjoyable alternative to sugary drinks — whether you're hosting guests or staying refreshed throughout the day.