Crema in espresso: an overrated indicator?

Crema. That thin golden layer that crowns a freshly extracted espresso. You've been taught to look at it with admiration, to judge a barista's skill by its thickness, to send back a coffee that didn't have enough of it. Yet, the reality is far more nuanced: crema is one of the most overrated concepts in the coffee world.

Here’s why.

What exactly is crema?

Crema is a foam formed during espresso extraction. Under 9 bars of pressure, the CO₂ dissolved in the cells of the roasted bean is suddenly released and trapped in an emulsion of water, oils, and lipids from the coffee. Very fine particles from grinding (the fines) also become suspended in this foam: and these are what form the characteristic dark streaks visible on the surface, the tiger stripes.

This emulsion rises and stabilizes on the surface of the cup until the pressure is released.

Why crema is overrated

1. Crema tastes bitter

Crema has a distinctly more bitter and astringent taste than the espresso it covers. Several factors contribute to this: the concentration of certain volatile compounds, suspended fines, and CO₂ forming carbonic acid upon contact with water; however, their relative contributions are still being researched. What is clear in practice: many professional baristas mix the crema into the espresso before serving, precisely to dilute this bitterness.

A thick crema doesn't make a bad espresso better. It can even make it worse.

If you want to test it yourself, you can simply remove the crema with a spoon before drinking your espresso. You'll get a significantly less bitter coffee, which can also be a good way to practically understand what crema adds - or doesn't add - to your cup.

2. More crema = fresher or darker roast: not better

The volume of crema primarily depends on two measurable variables:

• Bean freshness: After roasting, coffee gradually releases its CO₂ (degassing). Coffee roasted 3 days ago produces much more crema than coffee roasted 3 weeks ago. This isn't a difference in quality: it's the amount of residual CO₂.
• Roast level: The darker the roast, the more CO₂ the bean produces during the process and retains until extraction. Very dark roasted coffee mechanically produces more crema than light or medium roasted coffee, regardless of its quality.

Robusta is often presented as naturally more generous in crema than arabica. The link is real, but roasting plays an important role: robusta is generally roasted darker, so it also benefits from this effect. Industrial espresso blends often combine robusta and dark roast precisely to produce a visually abundant crema: an aesthetic argument, not a guarantee of in-cup quality.

3. Crema disappears in a few minutes

Crema quickly dissipates once the pressure is released. The espresso under the foam, however, remains. And it is this that contains most of the aromas. This ephemeral nature of crema illustrates its status well: it is a byproduct of pressure extraction, not the heart of the coffee.

4. The best specialty espressos often have little crema

Espressos made from specialty beans rated 85+ on the SCA scale (light to medium roast, high-altitude arabica varieties) often produce a thin, or even almost non-existent, crema. Yet, these are the espressos that reveal the most complex aromatic profiles: red fruits, citrus, flowers.

Judging an espresso by its crema is to miss what really matters.

What really matters in an espresso

• Extraction rate: generally between 18 and 22%, measured by the dose/yield ratio and extraction time
• Balance in the cup: acidity, sweetness, and slight bitterness in the right proportions
• Length on the palate: a well-extracted specialty espresso leaves a lingering finish
• Bean quality: variety, terroir, roasting, freshness: these factors determine the result

A good, well-extracted quality espresso blend will be flavorful with or without generous crema.

Crema as a technical indicator: and nothing more

Crema is not useless to observe. It can signal an extraction problem:

• Very light or almost absent crema: possible under-extraction (water too cold, grind too coarse, coffee too old)
• Very dark, almost black crema: possible over-extraction or over-roasted bean
• Homogeneous, reddish-brown crema: extraction went well technically, but it says nothing about the bean quality

In other words: crema can indicate that something went wrong. It does not guarantee that something went well.

A change of perspective

The next time an espresso with a thick, golden crema is placed in front of you, focus on what's in the cup: the aroma, the first sip, the balance. Our tasting guide gives you the keys to read an espresso with a keen eye.

Frequently Asked Questions about Crema

What is crema in an espresso?

Crema is a foam formed during pressure extraction. The CO₂ released by the bean is trapped in an emulsion of water and coffee oils, with fines (very small particles from grinding) in suspension. These fines form the dark streaks visible on the surface, called tiger stripes.

Is crema a sign of quality?

No. Crema volume primarily depends on bean freshness and roast level: two factors independent of the coffee's intrinsic quality. The best specialty espressos, made from light-roasted Arabica beans, often produce very little crema.

Why is crema bitter?

Crema indeed tastes more bitter than the espresso beneath it. Several elements contribute to this: suspended fines, CO₂ forming carbonic acid upon contact with water, and certain volatile compounds concentrated in the foam. This is why many baristas mix it into the espresso before serving.

Why does dark roasted coffee produce more crema?

During roasting, the thermal degradation of carbohydrates and other organic compounds produces CO₂. The darker the roast, the more CO₂ the bean produces and retains. During pressure extraction, this CO₂ is released and forms the crema: hence more foam with darker roasts.

Is an espresso without crema bad?

Not necessarily. The absence of crema can indicate coffee that is too old (CO₂ fully degassed) or a light roast. But a properly extracted specialty espresso can have very little crema and still be excellent.