21 Apr 2022 --- Guinness has begun the global rollout of its new hybrid beverage, Cold Brew Coffee Beer amid a boom in take home sales of Ready-to-Drink iced coffees. With approximately 2 mg of caffeine per can – the same as a decaf coffee – Guinness Cold Brew Coffee Beer is “best served ice cold, either straight from the can or in a glass,” according to the beverage giant.