A shot of espresso's crema directly affects how a milk coffee presents. Whether latte art holds its shape and whether the mouthfeel is smooth are largely determined by this layer of crema. Understanding what crema does makes it easier to choose beans and make milk coffees with confidence.

Crema is the layer of foam formed when carbon dioxide emulsifies with oils during extraction. The darker the roast, the fresher the beans, and the greater the extraction pressure, the thicker and denser the crema. For lattes and cappuccinos, crema's role goes beyond looking good: it supports the injected milk foam, letting latte art patterns form clearly; the smooth texture it brings makes the milk coffee taste fuller; and its rich aromatic molecules also enhance the flavor expression of the whole cup. An espresso with thin crema lets the milk foam disperse easily once poured, blurring the pattern and leaving the mouthfeel rather thin.

Paying attention to crema performance when choosing beans is about laying a foundation for milk coffee. The classic Mamba blend has excellent crema performance, yielding a golden, dense crema after extraction, and is a favorite of many milk coffee lovers; Brazilian beans have rich crema, and Queen's Estate produces even, fine crema when made as espresso; Golden Mandheling, after a dark roast, has heavy crema, with an espresso that is mellow and long-lasting, giving milk coffee plenty of body. Conversely, light-roasted beans usually have thinner, paler crema, and hold latte art slightly less well in milk coffee.

Crema also reflects extraction quality. Normal crema is golden with a brownish tint, fine in texture, and slowly dissipates when left to stand; if the crema is whitish and thin, the beans may be too fresh (excessive degassing) or the extraction may be insufficient; if the color is too dark with burnt-black edges, it may be over-extracted. These details all help judge whether the parameters are appropriate.

When making milk coffee, there are a few tips to improve crema performance: use fresh dark-roasted blend beans, preheat the portafilter and cup before extraction, and keep the dose and flow rate stable so the crema emulsifies fully. Choose beans with rich crema and pair them with stable extraction, and a cup of milk coffee with clear latte art and a smooth mouthfeel can be made easily at home.