QUESTION: I’ve heard some people talking about coffee crema and how it’s their favorite part of the espresso. I’m just not sure what it is. What is coffee crema? — Michael V.
ANSWER: Crema is a substance that’s a natural result of the process of making espresso—or at least of making espresso well. However, not all coffee drinkers agree that it contributes to the taste of a good espresso.
How Is Crema Formed?
The crema that rests on top of your espresso is the result of hot, high-pressure water coming through your coffee grounds as they begin to put out the carbon dioxide they’ve been emanating ever since they were roasted. The water is at such high pressure, it draws in oils from the coffee beans, and that’s where it meets the carbon dioxide. Those oil-loaded carbon dioxide bubbles then pass through the coffee beans, where the bubbles continue their journey. Some end up as the crema that rests on the surface of your drink.
Crema begins to disappear quickly as the fragile bubbles of carbon dioxide explode. Then all the coffee oils that they extracted from the beans are mixed into your coffee. As you may already know, the oils are what give coffee its flavorful aroma and taste.
Does Crema Affect Coffee’s Taste?
While some coffee drinkers prefer to stir in their crema or skim it off the top of their espresso because they say it has an ashy component, others value the crema as an essential part of the taste of a well-pulled espresso.
Those who say the crema improves the flavor of espresso say so because crema signals a longer aftertaste. The crema also adds to the decadent mouthfeel of the espresso and its taste in general because minerals in the crema are responsible for those flavors. They also praise the complexity and nuance of espresso shots that come complete with crema. However, crema isn’t the only indicator of a quality espresso, and it is possible to get a shot of espresso with crema that doesn’t taste good overall.
This happens because lots of factors go into the flavor of a quality coffee beverage. If the grind size, brew time, level of roast on the coffee beans or their freshness is off, the whole drink is at risk—crema or not. What the crema tells you is that the barista who made the drink knows what they’re doing. It also tells you that the coffee your barista was working with is made with quality beans and has the appropriate grind setting.
Very light roast coffees could be pulled by the best barista ever without resulting in a layer of crema. Because carbon dioxide is stashed in the coffee beans during the roasting process, this is a possibility. But in this case, the lack of crema doesn’t signal a bad shot of espresso. It’s simply a response to the amount of carbon dioxide available in the beans, which has nothing to do with your coffee’s flavor.
Should I Skim Crema Off My Espresso?
When someone skims crema from the top of their espresso, an ashy or bitter flavor is often touted as the reason. And it’s true that crema does have these flavors. However, bear in mind that unless you taste the crema on its own, these flavors are helping form the balance of elements that makes for a tasty espresso. The crema helps make up that slight burn and funk that many of us enjoy so much in our coffee.
Some who skim the crema say it’s because of the mouthfeel. They enjoy espresso more with less foam and a more streamlined overall texture. These are improved when the crema is removed. But be aware that crema plays a vital role in keeping your coffee from tasting dull and one-dimensional.
If what you’re looking for in your espresso is a sweet flavor and lighter overall mouthfeel, removing the crema may be for you. But most of us who drink espresso drink it for the full-bodied taste and enjoy the slight bitterness that comes from the crema.
More You Should Know About Crema
- Coffee with a dark roast has more carbon dioxide to devote to the crema than a light roast coffee. (Remember, the carbon dioxide is trapped in the bean before it makes it to your espresso.) That’s why dark coffees create more crema than ones with lighter roasts. You can also expect honey and natural coffees to create a larger layer of crema than other types, except for pre-washed coffee, which will come with less crema in your cup.
- Espresso made with more water also creates less crema than when a shot is pulled with less water. This happens when the coffee used in your espresso has a coarser grind than is ideal.
- A light-colored crema, one that disappears too quickly, or one thinner than 10 percent of the shot means the shot was under-extracted or that cold water was used. Under-extraction often happens when not enough coffee is used in the brewer or when the coffee grinder is set too coarse. Reasons you’re less likely to encounter include old coffee, cold water, or a setting of low pressure on the espresso machine.
- You can tell a lot about your coffee from the crema. The usual color is light tan, but you don’t have anything to worry about with a darker crema, though anything lighter might signal a problem. Because crema is made up of foam and bubbles, a gritty crema means that something has gone wrong. Large bubbles can also indicate an incorrectly pulled shot or other problems with the process of making your coffee.
- If the color of your crema is uneven or too dark, or its texture is too bubbly, the espresso used to make your shot may be over-extracted. Over-extracted coffee can come from grinding the beans too far or from measuring too much coffee. These signs can also mean that the water used to make the shot was too hot, or that the espresso was packed down too hard.
- Typically, crema lasts for around two minutes before it starts to disappear. A proper layer of crema will take up about a tenth of the espresso shot. One that starts to dissolve under less than a minute can point to a light roast or under-extraction.
- Crema isn’t all about taste. A study from Nestlé Research Lab and Nespresso showed that just seeing crema present on an espresso can influence the coffee drinking experience. Because there’s crema on your coffee, you expect certain things, such as that the coffee will be premium and smooth. Not only that—the thickness of the crema determines how much influence the crema has on your perception.
- If you, like a lot of others, prefer Arabica beans to Robusta, you may want to change up your order if you like a lot of crema on your espresso. Robusta beans are known for generating a lot more crema than their Arabica cousins, and a more aromatic one at that. However, you will be making a sacrifice on taste, as Arabicas are more popular than Robustas for that reason.
- Wonder why the one to ten ratio is the recommendation for crema in a shot? Too much crema leaves you with too little room for coffee.
- You may see espresso machines on the market with lots of automated controls. These can sometimes make a faux “crema” that is not the result of carbon dioxide and oil, like the crema we love. On machines that don’t serve the faux “crema,” watch out, because the automated models that don’t make the fake stuff will usually make less crema.
Some of us think of crema as a layer, like a lid over the top of the coffee that keeps in all those tasty aromatics. However, that Nespresso and the Nestlé Research Lab study showed that this isn’t quite true. The crema part of your coffee actually helps move aromatics up into the air where we can enjoy them up until the first three minutes. Then it solidifies into something aromatics can’t pass through and keeps them in the cup. So if you drink your espresso quickly (or at least in three minutes or less) you can thank your crema for the scent you’re enjoying.