Despite the intimidating sound of the name, the cold brew method is perhaps the most straightforward of all. There is no specialised equipment or knowledge required; simply mix filtered water and your favourite tea or tisane in a jug, and allow it to steep at least 4 hours, or 12 hours overnight in the refrigerator.
What makes cold brew so cool?
It's a fun alternative to brewing the traditional way, and you might even pick up on new flavours you never tasted before. Unlike a hot brew that has been chilled to make an iced tea, the liquor from cold brewing is often sweeter and mellower. The difference between a hot and cold brew is noticeable with all teas, but particularly noted with black, pu’erh and highly oxidised oolong teas, which are renowned for producing a strong, flavourful, dark brew with hot water. Because only cold water is involved, less colour (pigment), caffeine and a lower concentration of tannic-yielding catechins are released. In short, your infusion is lighter: in colour, in caffeine and taste.
In this recipe, we've selected Endeavour Breakfast, one of our most popular black tea blends, to highlight the points above. Although in some cases there may be little difference in the appearance of the wet leaf between cold and hot brew, there is a stark contrast between the colour of the liquor: as expected, the hot brew yields a deep, almost hazelnut coloured cup, while the cold brew is as light and clear as new amber.
From a tasting perspective, the cold brew of Endeavour Breakfast is surprisingly terse, with a quick succession of notes including cacao and wood smoke, offset with a gentle spice and an underlying sweetness. There is no astringency and an almost imperceptible element of tannin. We tried this cold brew served over a few ice cubes in a short glass, which made for a delightful, almost whisky-like iced tea experience.
Left: hot brew tea and spent leaves unfurled by extreme heat; right: cold brew tea with its leaves still tightly curled, its essential oils gently infused overnight in cold filtered water
How to perfect cold brew tea
Although the cold brew method will always produce some result, the effect may vary dramatically from your experience of a hot brew of the same tea or tisane. Hot water rapidly penetrates the parched outer shell of a preserved ingredient and rehydrates from the outside in, leading to an initial burst of aroma. Over a short period of time in contact with the heated water, the flavours and aromas will express themselves fully. In contrast, cold water will release their goodness of the ingredients over a longer period of time.
For this reason, it's a good idea to rinse your tea or tisane with boiling water before preparing your cold brew. The hot water will soften the ingredients and allow easier transmission of the flavour, colour and aroma in cold water. Furthermore, the hot water may relieve some of the impurities of the ingredients, such as dust, bacteria, bitter flavours, preservatives or unwanted chemicals that may have built up.
While you can prepare a cold brew from just about any tea or tisane, there are some occasions in which the hot brew method is preferable to avoid a disappointing final product. For example, some aromatised teas, particularly those scented only with a natural flavouring liquid, may be less suitable for cold brewing. The reason is that the flavouring is usually contained in an alcohol solvent base that is activated and released with hot water. As a result the full extend of the flavour may not manifest in cold brewing. Nevertheless, some aromatising solutions, such as concentrated flavouring capsules and concentrated artificial flavours possess a robust chemical composition that may be tasted in cold brewing as well.
Through our experiments we have found that the fresher the ingredient, the more rapid and effective the infusion in cold water. Poor quality ingredients will lead to a poor result. Start with great quality, fresh teas, clean filtered water and fresh fruits, herbs and spices for garnish.
Furthermore, because of the minimal processing involved, green and white teas are ‘fresher’ and tend to produce a satisfactory cold brew tea in a shorter time: perhaps 4-6 hours. Generally speaking, black, oolong, yellow and pu’erh teas undergo significantly more processing and drying, meaning that a longer infusion time is recommended: perhaps 6–12 hours. The same rule applies for tisanes and aromatised teas.
If you prefer a stronger tasting tea, you can either slightly increase the quantity of tea or tisane per cup (240mL), or steep for longer. The longer the infusion, the more concentrated the flavour, caffeine content and cans, so be sure to experiment with steeping times to find an ideal time that suits your palate.
Cold brewed Endeavour Breakfast
- Measure 3 grams (2 semi-heaped teaspoons) of Endeavour Breakfast for every cup (240mL) of water.
- Place into a jug and fill with cold filtered water. Cap with a lid and place into the refrigerator.
- Chill for 4-12 hours. Strain into another clean jug.
- Add your sweetening agent to taste (about 1.5 tsp of sweetener per 500mL) and stir vigorously. If using a granular sweetener, it may help to dissolve it in a little hot water first.
- Serve straight or with a garnish (see below).
- Peppermint, spearmint, sage, lemon verbena, lemon myrtle, stevia leaf
- Macerated berries (strawberry, blueberry, raspberry)
- Citrus fruits and peels (lemon, citron, orange, yuzu)
- Sweeteners (raw honey, cane sugar, simple syrup, maple or golden syrups, raw coconut sugar, fruit juice or nectar)