Jun 21, 2013 (Talk of the Nation) — 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.
This text will be replaced
Missing some content? Check the source: NPR
Copyright(c) 2013, NPR