Coffee
From Halopedia, the Halo wiki
Coffee is a human beverage, created with ground coffee beans, grown on plants which are native to Earth. The beverage has been widely popular for centuries among humans, primarily because it naturally contains the drug caffeine, which is a stimulant. Coffee is served in numerous restaraunts and businesses such as Jim Dandy roadside diners. It is almost always served hot[1]. It is also commonly avaliable on Food & Drink Dispensers which are standard on UNSC military vessels[2].
Dr. Catherine Halsey was a heavy drinker of Coffee throughout most of her professional life[3]. Her office would often be filled with cups of coffee of varying ages, which she would drink hot or cold[4].
