Espresso Crema: What It Is, Why You Have None and How to Get More

Every few weeks a customer sends us a photo of a shot that looks like a gray puddle with a few big bubbles floating on it, and the message underneath says, "I think I broke my machine." Almost never. Espresso crema is the tan foam on top of a shot, and it is mostly carbon dioxide from the roast, pushed into the water at about 9 bar and let loose again the second the shot hits the cup. When it comes out thin or missing, the cause is nearly always one of four things: old beans, a coarse grind, a short dose, or a basket that never built pressure. Here is how I work out which one you have.

The short version

• What crema is: CO2 from the roast, dissolved under pressure, then released as bubbles that coffee oils and fine particles hold together.
• Biggest lever: freshness. Published measurements found bean variety and freshness drive crema volume far more than small grind tweaks do.
• Quick check: a 1:2 shot, say 18 g in and 36 g out, in roughly 25 to 30 seconds is where most people land when dialed in.
• Not a quality score: crema hints at freshness and extraction. Taste the shot before you chase more foam.

What is espresso crema?

Roasting packs the bean with gas, and about 87% of it is carbon dioxide, according to a review of espresso foam in the journal literature. Hot water at roughly 9 bar forces a good share of that CO2 into solution. When the coffee leaves the puck and meets normal air pressure, the gas comes back out as tiny bubbles, and emulsified oils and bean fragments wrap each one in a thin film. Think of cracking a bottle of sparkling water, except here the oils keep the foam standing for a minute or two.

This is why freshness decides so much. The same review measured 4.0 to 8.6 mg of CO2 per gram of freshly ground coffee, averaging 5.7 mg/g, and robusta (6.9 mg/g in their sample) held more than arabica (4.6 mg/g). Less gas in the cup means less foam, however carefully you pull the shot.

Is crema a sign of a good espresso?

Crema is a clue, not a grade. A thick layer tells you the beans were fresh enough and the puck held the water back long enough to build pressure. It says nothing about sweetness, acidity or bitterness. I have served shots with gorgeous tiger-striped foam that tasted like burnt toast, and one pale-capped light roast that was the best thing on the menu that day. If I had to pick between the two cups, I would drink the pale one every time.

Roast and bean type shift the baseline, too. Lighter roasts usually give a thinner, paler cap, and a straight arabica gives less foam than a blend with some robusta. Dark roasts often look like they make more crema, though you pay for it in the cup if the roast is heavy. So if your single-origin light roast shows only a thin ring, that may be perfectly normal. Taste the cup.

Why is there no crema on my espresso?

Match what you see in the cup to a likely cause before you touch a dial. I have watched people change grind, dose and temperature in one go and then have no idea which one helped. Keep a scrap of paper by the machine and write one line per shot.

First suspect: the age of the bag

If you made me bet, my money goes here first. When someone writes in about crema, my first question is what the bag says and whether that date is the roast or a best-before. Roasting makes the CO2, and the bean leaks it slowly afterwards. Sources disagree on the ideal window (some say 4 to 14 days off roast, others 7 to 30), so I treat roughly a week to a month as the sweet spot. Read the roast date, not the best-before date; Flair, for one, tells customers to ignore best-by dates because they tend to be wildly optimistic. And if the beans are around two months old, Story of Coffee notes you will get little crema whatever you do.

Good storage keeps a bag inside that window, but it cannot rescue a stale one. We keep ours in an airtight stainless coffee canister with a one-way valve and date dial and turn the dial to the roast date, so nobody has to guess. It is a sealed canister with a degassing valve, not vacuum storage. The full routine is in how to store coffee beans at home.

Next: a grind that is too coarse, or a dose that is too small

If the shot gushes through in under 20 seconds and looks like weak tea with a few bubbles, the puck never resisted the water, so pressure and CO2 transfer never happened. Go one step finer, run a few grams through to clear the old setting out of the grinder, then pull another shot and time it from the moment the pump starts. Keep going until a 1:2 shot, 18 g in and 36 g out, lands near 25 to 30 seconds. If it then crawls past about 35, back off one click. Our walkthrough on how to dial in a coffee grinder covers the numbers on the dial, and the espresso grind size dial-in guide covers the timing side.

Dose is the sneaky one. A basket rated for 18 to 20 g that you load with 15 g leaves a shallow puck, a fast flow and patchy foam, and eyeballing it is how most people end up there. Weigh every dose until it becomes habit. We use a coffee scale with timer that starts counting when liquid hits the cup, so the 36 g and the clock sit on one screen. Honestly, I would buy a scale before I bought a fancier grinder. If the shot gushes or the puck is soggy afterward, why is my espresso puck wet goes deeper.

Rarely, but check: is the machine really making 9 bar?

Pressure is rarely the main cause, so do the cheap checks first. But if the beans are fresh, the grind is right, the basket is properly dosed and crema is still weak, the machine deserves a look. Around 9 bar at the puck is the usual target, and the 15 bar on the box is the pump's rating, not what reaches the coffee. A pressure gauge on a blind portafilter costs roughly $20 to $40 according to The Coffee Locator and shows you the real number.

Crema that vanished overnight on the same beans, or a shot that runs fast even at a fine grind, can point to a worn pump, over-pressure valve or group gasket. Water temperature matters less for crema volume than people think, but a cold machine gives pale, sour shots, so let a single boiler warm up and flush the group before the first pull. If the machine has not been cleaned in months, our group head cleaning guide is a good first step.

Or the puck is channeling

White holes or lopsided streaks in the crema usually mean water found a crack in the puck and rushed through it. Uneven tamps and clumpy grounds are the usual triggers. A level tamp matters more than a hard one, and stirring the grounds with a needle tool before tamping breaks up clumps. When I suspect this, I knock the puck out and look at its surface for pits and cracks. If you would rather see channeling than guess, a bottomless portafilter shows it as spurting jets. We wrote how to fix channeling with better puck prep and how hard to tamp espresso for the details.

Is crema from a pressurized basket real?

Not in the same way. A pressurized, or double-wall, basket has a second wall with one tiny exit hole. The flow squeezes through that hole, pressure builds in front of it, and the foam appears when the pressure drops on the far side. It looks thick and golden even with stale or pre-ground coffee, but it is airier and bubblier, and it forms after the extraction rather than during it. True crema forms inside the puck, where CO2 and oils meet under pressure.

The story I hear most: someone swaps a pressurized basket for a standard one, the crema shrinks, and they decide the new basket is faulty. It is not. You are finally seeing the real thing, and it tells you about your beans and grind. Our pressurized vs non-pressurized basket guide covers which one suits your machine and grinder.

How to get more crema, step by step

This is the order I work in when someone hands me a pale shot. Change one thing at a time, and if you cannot resist changing two, at least write both down.

1. Check the roast date. If it is older than about a month, buy a fresh bag before you change anything else.
2. Grind right before the shot, not ahead of time.
3. Weigh the dose to your basket's range, for example 18 g for an 18 g double basket.
4. Level and tamp evenly, rim to rim, and use a needle tool first if the grounds are clumpy.
5. Start the timer with the pump. Aim for about 36 g out in 25 to 30 seconds, moving the grinder one click at a time.
6. Only if all of that is right and the foam is still thin, check pressure and the group gasket.

Measure the liquid, too. A cup marked at 30, 60 and 90 ml, like our 90 ml stainless measuring cup, lets you see the volume and the crema layer before you pour. It is a liquid cup, not a dosing cup. The ratios behind these numbers are in espresso shot weight vs volume and how to make espresso at home.

If the foam looks fine and the shot still tastes wrong, stop adjusting for crema. Sour or bitter cups have their own diagnosis in why coffee tastes sour or bitter.

Mistakes I watch people make chasing crema

Grinding finer and finer on stale beans. You choke the machine, the shot turns bitter, and the crema is still gray. The beans were the problem all along.

The second one is judging a bag on day two. A bag only a few days off roast can pour a giant, bubbly crema that collapses within moments, so give it a few days before you decide anything. Related trap: trusting the 15 bar sticker on the box. That number describes the pump, not the puck.

Then there is rating the shot by its foam. Crema carries some of a shot's bitterness, which is why some baristas skim a spoonful off before drinking. Try it once on your own shot and see what you think.

Last, and the one that catches people after a basket upgrade: switching baskets and forgetting to re-dial. Going from pressurized to standard means a finer grind, a weighed dose and fresher beans, all at the same time. Expect a rough first week.

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Espresso crema FAQ

Why is there no crema on my espresso?

Look at the roast date first. If the bag is more than about a month old, most of the carbon dioxide that builds crema has already left the bean, and nothing at the machine will bring it back. With fresh beans, the next suspects are a grind that is too coarse (the shot runs under 20 seconds) and a dose too small for the basket. Pre-ground coffee almost never gives much crema, so if that is what is in the hopper, start there.

Is crema a sign of good espresso?

Only partly. It tells you the coffee is fresh and the shot built pressure, but not whether it tastes good. A thick crema can still be bitter or sour, and a modest one on a well-extracted light roast can taste excellent. Drink the shot before you judge the foam.

Why does my crema disappear so fast?

Old beans or a coarse grind usually leave large, unstable bubbles that pop quickly. The opposite case happens too: beans only a few days off roast can throw a huge, bubbly crema that collapses because they are still degassing hard. If your bag just arrived, give it several days to settle before you blame the machine.

Does a dark roast make more crema?

Often, yes, and the foam looks darker and heavier. Published measurements found more carbon dioxide in dark roasts than in medium roasts. The catch is flavor: a dark roast can give you plenty of crema and a bitter cup, so do not pick beans by foam alone.

Do pressurized baskets make real crema?

They make plenty of foam, but it forms differently. A pressurized (double-wall) basket restricts the flow through a tiny exit hole, and the foam appears once the pressure drops past that hole. It is airier and bubblier than the oil-stabilized crema from a standard basket, which is why it shows up even with stale or pre-ground coffee. Pretty, but not the same thing.

Can you get crema from pre-ground coffee?

Rarely much. Grinding releases a large share of the trapped carbon dioxide within minutes, and that gas is what builds crema. Grind just before the shot, even with an inexpensive burr grinder, and you will see the difference on the very next pull.

Does robusta make more crema than arabica?

Yes. A study of espresso crema found larger crema volume from robusta than arabica, while arabica crema was more stable thanks to its higher lipid content. That is why traditional Italian blends often include some robusta, and why crema volume says little about bean quality.

What bar pressure do you need for crema?

About 9 bar at the puck is the usual target, and 8.5 to 9.5 is a sensible window. The 15 bar printed on many home machines is the pump rating, not the brew pressure. If the beans are fresh, the grind is right and the dose is full but crema is still weak, put a pressure gauge on a blind portafilter. It will tell you quickly whether the machine is at fault.

Sources

• Neglected Food Bubbles: The Espresso Coffee Foam (PMC), CO2 share of roast gases, CO2 per gram, arabica vs robusta.
• Investigation of the factors that affect the volume and stability of espresso crema (PubMed), freshness, variety and basket size effects.
• Flair Espresso, What is crema?, how crema forms, roast date vs best-by date.
• The Coffee Locator, How to Get More Crema on Espresso, symptoms table, 25 to 30 s window, pressure gauge, 9 bar vs pump rating.
• Story of Coffee, Espresso Crema: Why You Have None, beans around two months old, pressurized baskets.
• Kaffeemacher, Double-walled filter basket, how pressurized baskets form foam.
• Brewed Barista, Why Your Espresso Crema Disappears, mechanical causes and crema as an indicator.

Specs checked on product listings 2026-11-10 (Asia/Shanghai). Times and ratios are starting points; adjust to your beans, grinder and machine.