Coffee’s Natural Creamer
Coffee beans are filled with oils that emerge from coffee grounds under high pressure. These oils form the crema—the frothy stuff on top of an espresso. In the last installment of Science Friday’s series on coffee, food-science writer Harold McGee, author of On Food and Cooking, explains the chemistry of crema.
Flora Lichtman is host of the podcast Every Little Thing. She’s a former Science Friday multimedia producer.