a thin layer of light-brown foam (= small bubbles) that forms on the top of some types of strong coffee

The machine makes a decent cup of coffee, but there's no crema. 这台机器能做出不错的咖啡，但是没有咖啡脂。

The espresso has a good crema and a pleasing, slightly chocolate taste. 意大利浓咖啡有一层很棒的咖啡脂和一种令人愉悦、淡淡的巧克力味道。