In brief
Crema is the foam on top of a fresh espresso. Roasted coffee holds carbon dioxide. Under brewing pressure, water dissolves more of that gas, and in the cup it escapes as tiny bubbles that collect at the surface.
Proteins and carbohydrates in the coffee coat those bubbles and hold the foam together. Honest Coffee Guide calls these compounds surfactants. Oils, on the other hand, work against foam.
Crema looks like a sign of quality, but it is a weak one. A stale or badly pulled shot makes less of it. A thick, rich layer does not promise a good-tasting shot.
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Why does espresso have crema but drip coffee doesn't?
Pressure. Perfect Daily Grind explains that water under pressure dissolves more carbon dioxide. When the shot leaves the machine, the liquid can't hold all of that gas, so it comes out as bubbles.
Gravity brewing never builds that pressure, so pour-over and drip don't form crema. Britta Folmer, quoted by Perfect Daily Grind, says pressure is "definitely crucial" for crema to form.
Wikipedia credits Achille Gaggia's high-pressure lever machine, first sold in 1948, with producing crema.
Does more crema mean a better espresso?
No. Crema tells you something about freshness and extraction, but not how the shot tastes. Honest Coffee Guide puts it plainly: you could over-extract a low-quality dark roast "and still get a thick rich crema."
A specialist quoted by Perfect Daily Grind says crema shows the coffee is fresh and well extracted, then adds that "you can't really know how the coffee is going to taste just by the crema." Taste still decides.
What affects how much crema you get?
Freshness, roast, species and processing all play a part. Both Honest Coffee Guide and Perfect Daily Grind agree on the main patterns.
| Factor | Effect on crema |
|---|---|
| Fresher beans | More crema; CO2 fades as coffee ages |
| Darker roast | More crema, and darker in color |
| Robusta | More crema than arabica, but less compact and aromatic |
| Natural and honey process | Usually more crema |
So a thick layer can say as much about the beans as about how the shot was pulled.
What can crema tell you about extraction?
It gives rough visual clues, worth checking against taste. Perfect Daily Grind links light, thin crema that vanishes quickly to under-extraction. Causes include too coarse a grind, too little coffee, low pressure, stale beans or cool water.
Dark, uneven, bubbly crema points the other way, toward over-extraction. Causes include too fine a grind, heavy tamping or water that is too hot. In both cases, the grind is usually the first thing to adjust.
Should you stir, skim or drink the crema?
Honest Coffee Guide recommends stirring it in, but this is contested. Crema on its own tastes bitter and drier than the rest of the shot, according to Honest Coffee Guide.
Some baristas remove it. Perfect Daily Grind reports that Michael Harris Conlin, a three-time Philippine Barista Champion, skims crema for a "cleaner and less bitter" cup. James Hoffmann called crema "rubbish" in 2009.
The other side has evidence too. Perfect Daily Grind cites research that crema helps release aroma and adds body. It reports that Coffee Collective's 2008 tests found skimming gave a cleaner cup but lost body. Try it both ways with your own coffee.
Does your grinder affect crema?
Indirectly, through extraction. A grind that is too coarse gives a fast, thin shot with pale crema. A grind that is too fine can give dark, patchy crema and a bitter taste.
An espresso grinder that adjusts in small steps lets you land between those two. The grinder finder can narrow the list to espresso grinders.
Sources
- Honest Coffee Guide: What is coffee crema?
- Perfect Daily Grind: Crema, how it's formed, what it tells us, and how to learn from it
- Perfect Daily Grind: Why removing crema from espresso is dividing specialty coffee
- Wikipedia: Espresso
By Jeff Gluck · Checked Oct 21, 2026