What is crema on espresso made of?

Crema is an emulsion of CO2 gas, oils and dissolved solids from the coffee, whipped into a foam by hot water forced through the grounds at roughly 9 bars of pressure, per SCA extraction standards. The CO2 comes mostly from roasting — it's trapped in the bean and released during brewing — which is also why crema is a byproduct of pressure and freshness, not a mark of a 'stronger' shot.

Is more crema always better?

No. A very thick crema is often a sign of a fresh, dark-roasted or robusta-heavy bean, not necessarily a better-tasting shot — some of the best specialty light roasts pull with a thinner, tan-colored crema because they hold less CO2 and less roast-driven oil. Crema is a useful diagnostic for freshness and extraction, but it isn't a direct measure of quality or flavor.

Why does my espresso have no crema?

The most common cause is stale beans — coffee loses most of its CO2 within 2 to 3 weeks of roasting, and stale grounds simply can't foam the way fresh ones do. Other causes include pre-ground coffee (which degasses even faster than whole bean), too-coarse a grind that lets water through before it can build pressure, or a pump/boiler that can't hit the roughly 9-bar extraction pressure espresso needs.

How long should crema last on an espresso shot?

A healthy crema should hold for roughly 1 to 3 minutes before noticeably breaking up and thinning, though it starts changing color and texture within the first 30 to 60 seconds. Crema that vanishes in a few seconds usually points to stale beans or under-extraction; crema that never forms at all usually points to a pressure or freshness problem further upstream.

What is tiger striping in espresso crema?

Tiger striping is the mottled, streaked pattern of light and dark bands sometimes visible on top of the crema, caused by uneven oil distribution as it emulsifies during extraction. It's often associated with well-extracted shots from freshly roasted beans, but its absence doesn't mean a shot is flawed — plenty of excellent, evenly-extracted shots pull with a smooth, unstriped crema instead.

Espresso Crema (2026): What It Actually Is and How to Get More of It

Quick Answer: Espresso crema is the reddish-brown foam layer on top of a shot, formed when hot water at roughly 9 bars of pressure forces CO2, oils and dissolved solids out of freshly ground coffee and whips them into an emulsion, per SCA extraction standards. Thick, long-lasting crema mostly signals fresh beans (coffee loses most of its CO2 within 2–3 weeks of roasting) and adequate pump pressure — it is a useful freshness and extraction diagnostic, but not a direct measure of taste quality. No crema almost always means stale or pre-ground beans, a grind that’s too coarse, or a machine that can’t build enough pressure.

Crema gets treated as the mark of a “real” espresso shot, but it’s really just chemistry: hot water under pressure grabbing CO2 gas, coffee oils and dissolved solids from freshly roasted grounds and whipping them into a foam as they exit the portafilter. Understanding what’s actually happening in that foam explains why the same machine and the same grind setting can produce a thick, long-lasting crema one week and almost none the next — and why chasing crema for its own sake can steer you toward the wrong fix.

What crema is made of

Crema is an emulsion, not a separate ingredient — it forms from three things already inside the coffee: carbon dioxide gas released during roasting and trapped in the bean, oils drawn out of the grounds by hot water, and fine solids suspended in the extraction. Roasting is what puts most of that CO2 there in the first place, and it starts leaving the bean the moment roasting ends. That single fact — CO2 escaping over time — is the reason freshness dominates almost every crema problem below.

Why crema disappears: the freshness clock

Coffee loses the majority of its CO2 within 2 to 3 weeks of roasting under normal storage, and pre-ground coffee degasses even faster than whole bean because grinding exposes far more surface area to the air. That’s the single biggest reason a shot that crema’d beautifully in week one looks flat and foamless by week four with the exact same machine and grind setting — there’s simply less gas left to whip into foam. It’s the same degassing curve that drives dial-in changes day to day; see our how to dial in espresso guide for how freshness shifts flow rate independent of crema.

Fresh-Roasted Whole Bean Espresso

Buy dated, roast-to-order bags · look for a roast date, not a "best by" date

A printed roast date lets you judge freshness directly — aim to use beans within 2-4 weeks of roasting.
Whole bean holds CO2 far longer than pre-ground; grind only what you need per shot.
Skip anything with only a "best by" date stamped 12+ months out — that's not a freshness signal.

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Running low on beans mid-week is the easiest way to end up pulling from a stale bag out of convenience — Amazon Fresh can have a new bag on your doorstep before the old one is worth finishing.

Pressure, grind and machine factors

Freshness sets the ceiling on how much crema is possible; pressure and grind decide whether you get there. Espresso extraction standards call for roughly 9 bars of pressure, per SCA reference specs — enough force to push water through a tightly packed, fine grind fast enough to trap gas as foam rather than let it bubble out slowly. A grind that’s too coarse lets water rush through before it can build that pressure, producing a thin, fast-vanishing crema even with fresh beans. Pump-driven machines with a properly sized boiler hold that pressure consistently shot after shot; older or underpowered pumps can struggle to reach it at all, which is one reason a machine upgrade sometimes “fixes” a crema problem that grind adjustments alone couldn’t. Our best espresso machine guide covers pump specs across current models if a weak pump is the suspect.

Grind size interacts with pressure directly: too fine and the shot chokes, running slow with a crema that can look thick but taste bitter and over-extracted; too coarse and water channels through too fast for real pressure to build, undercutting crema along with extraction. Getting grind size right is as much a crema fix as a taste fix — see our espresso grind size guide for the full micron range and how small adjustments change shot behavior.

What tiger striping actually indicates

Tiger striping — the mottled light-and-dark banding sometimes visible across the crema’s surface — comes from uneven oil distribution as the emulsion forms during extraction. Baristas often treat it as a good sign because it tends to show up on fresh, well-extracted shots, but its absence isn’t a red flag on its own: an evenly golden, unstriped crema from fresh beans and a clean pull is just as legitimate. Chasing a specific visual pattern is less useful than checking the two things that actually drive crema — bean freshness and consistent grind/tamp technique. Uneven tamping is a common hidden cause of both patchy crema and inconsistent taste; a WDT tool breaks up clumps before tamping and removes one more variable.

Crema, by the numbers

9 bars — the reference extraction pressure for espresso per SCA standards, and the pressure needed to whip trapped CO2 into a stable foam.
2–3 weeks — roughly how long coffee retains most of its post-roast CO2 under normal storage before crema potential drops off.
1–3 minutes — how long a healthy crema layer typically holds before visibly breaking up and thinning.
30–60 seconds — how quickly crema begins changing color and texture even on a well-pulled shot, which is why crema is best judged in the moment, not from a photo.

The bottom line

Crema is a byproduct of fresh, degassing coffee meeting roughly 9 bars of water pressure — not a direct measure of how good a shot tastes. If crema has thinned out or disappeared, check bean age first (most coffee loses the bulk of its CO2 within 2-3 weeks of roasting), then grind size, then whether your machine can actually hold espresso-range pressure. Thick tiger-striped crema is a nice sign of freshness and a clean pull, but plenty of excellent shots — especially lighter specialty roasts — pull with a thinner, smoother crema and taste better for it. For the mechanics of getting a consistently balanced shot beyond crema alone, see our how to dial in espresso guide.