Cold Brew Tea
Cold brew tea is made by steeping leaf in cold or room-temperature water for several hours, giving a sweeter, less bitter cup than hot brewing.
Definition
Cold brewing extracts tea with time instead of heat. Leaf is placed in cold water, usually in a refrigerator, and left for 4-12 hours before straining. In Japan this is called mizudashi (水出し), and mizudashi sencha and gyokuro are sold specifically for it. Temperature changes what comes out of the leaf. Caffeine and the more astringent catechins, especially EGCG, dissolve far more readily in hot water than in cold, while amino acids such as L-theanine and many aroma compounds extract well at low temperature. The result is a cup that tastes sweeter and smoother, with noticeably less bitterness, even when brewed strong. Cold brew suits Japanese green teas, Taiwanese oolongs, white teas, and many Chinese and Indian black teas. Heavily roasted oolongs and smoked teas can turn flat, because their character depends on heat-released aromatics. Cold brewing should not be confused with flash-chilled iced tea, which is brewed hot and double-strength, then poured over ice.
In Depth
Starting ratio: 8-10 g of leaf per liter of cold filtered water, steeped 6-8 hours in the fridge for green tea and 8-12 hours for oolong, black or white tea. Japanese green teas extract fastest and can taste grassy past about 6 hours.
Food safety: brew in the refrigerator rather than on the counter, use a clean bottle, strain out the leaf at the end, and drink within about 24-48 hours. Cold water does not sterilise anything.
Cold brew tea generally contains less caffeine than the same leaf brewed hot, but how much less depends on the tea and the steep time; long, strong cold brews can still deliver a meaningful dose. Expect the liquor to look paler than a hot brew of the same strength. Cold-brew bottles with a built-in filter in the neck, sold for Japanese tea, make straining a single pour.
See Also
- Mizudashi
- Iced Tea
- Summer Tea Brewing