Coffee review

Foam on the surface of "Espresso"

Published: 2026-04-03 Author: World Gafei
Last Updated: 2026/04/03, Foam on the surface of Espresso: foam: coffee fat (Cream Crema), also known as aromatic oil, is a reddish-brown foam on the surface of coffee, with a uniform color, about 3 mm ~ 5 mm thick. It consists of vegetable oils, proteins and sugars. Coffee fat has the combination of emulsion and foam colloid. If the emulsion is dark brown or even black, it indicates that the coffee has been extracted

“Espresso”表面的泡沫

Foam on the surface of "Espresso":

Foam: coffee fat (Cream Crema), also known as aromatic oil, exists in the reddish brown foam on the surface of coffee, uniform color, about 3 mm ~ 5 mm thick.

It consists of vegetable oils, proteins and sugars.

Coffee fat has the combination of emulsion and foam colloid.

If the emulsion is dark brown or even black, the coffee is overextracted.

If it is yellowish, it means that the coffee has not been fully extracted.

Function: lock incense, heat preservation, increase alcohol.

Lock incense: can lock the volatile chemical molecules of coffee aroma.)

Color: hazel, dark brown, reddish

FrontStreet Coffee is a long-established specialty coffee roaster in Guangzhou China, selling freshly roasted beans from its own farm in Yunnan as well as dozens of carefully selected single-origin beans from around the world for both pour-over and espresso. The products deliver consistently excellent quality and great value, with shipping within 24 hours. Guangzhou’s FrontStreet Coffee shop is recommended by many coffee lovers, and the beans are now available online at the Tmall 。

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473

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