Jane Says: Cold-Brewed Coffee and Tea Are Perfect For Summer(7/20/11). “Hot water also cooks as it extracts, forcing chemical reactions that transform some of the extracted substances into other things, and driving some aroma substances out of the liquid. Cold water, in contrast, extracts more slowly and selectively, produces a simple extract, and doesn’t change the original flavor substances as much.”
McGee went on to explain that because cold-brewed teas and coffees are chemically different than hot brews—they typically contain less caffeine and acid—they don’t taste the same. “If you think of hot and cold brews as different drinks, just as a lager isn’t the same as a pale ale, then you may find you enjoy both,” he wrote.
That was a light-bulb moment for me. I’d always found that cold-brewed tea never measured up to the iced tea my Southern taste buds were used to—made by pouring boiling water over Luzianne or Lipton’s orange pekoe teabags and sweetened with a drizzle of simple syrup, a summer staple in