How to make cold brew tea

For a first batch, use 5 g of tea per 500 ml of cold drinking water and steep in the fridge for 4–8 hours. This is a starting point; check earlier if the package gives a shorter time. Cold brewing often tastes mellow, but it can still produce bitterness or astringency.

Cold-brewed oolong and black tea blend.
Photo: ありわかだ．．． · CC BY-SA 2.0

Steps

Choose the tea and clean your equipment. Choose tea that the producer labels as suitable for cold brewing. Green, white or light oolong is an approachable starting choice. If the instructions require boiling water, follow them and cool the finished infusion instead. Do not apply this recipe to arbitrary herbal or fruit blends. Wash the pitcher, lid and strainer. Use fresh drinking water without an unpleasant taste; bottled water is not essential.
Refrigerate straight away. Add the water, cover and put the vessel in a fridge at 4 °C or below. Do not leave it overnight on the counter or in the sun. Refrigeration slows microbial growth but does not sterilise tea. A quick rinse does not replace heat treatment either.
Taste and strain. For this recipe, start tasting at around 4 hours. If weak, keep steeping in the fridge and check again later. Once the strength suits you, strain into a clean container with a lid. Adjust either leaf quantity or time for the next batch, one at a time. Ice is fine: it chills and dilutes the drink. Sugar, lemon or other additions are optional and best added to your individual serving.
Make a small batch. Keep the tea covered in the fridge. For a homemade batch, plan to finish it within 24 hours of starting preparation; follow a shorter package instruction where given. This is not a safety guarantee if storage conditions are poor. Pour into a separate cup rather than drinking from the shared pitcher. Use fresh leaves and wash the equipment again for the next batch.

Questions and answers

Does cold brew have less caffeine?

Not necessarily. Tea, leaf quantity, water, time and serving size all affect the amount. A mellow taste does not mean low caffeine; cold brew is not automatically an evening or caffeine-free drink.

Can I use black tea or shu pu-erh?

Yes, if the producer’s instructions allow cold brewing for that product. Expect a different flavour from green tea or light oolong. The tea category alone does not rule it out.

How is it different from tea poured over ice?

Cold brew infuses the leaves in cold water. Iced tea can be brewed hot, strained and chilled quickly. The brewing temperature changes the flavour.