What is an espresso crema?
A well-prepared espresso has a thick, golden-brown foam layer on the surface, the so-called crema (the Italian word crema means cream). For many coffee lovers, a full and firm crema is the most important thing about espresso. A firm crema is, therefore, a significant and typical characteristic of the quality of an espresso.
But what makes a good crema? And how is the crema made? We answer these and other questions in this article.
How is crema made?
Crema is created because water under very high pressure dissolves the carbon dioxide (CO2) created in the beans during roasting. The water becomes saturated with carbon dioxide and releases this gas in the form of tiny bubbles. They form a stable layer of foam on the espresso called the crema. Crema consists of emulsified oils, proteins, water vapor bubbles, and carbon dioxide (CO2).
When the first espressos in Italy were prepared with a hand lever machine in the middle of the 20th century, people were initially skeptical about the previously unknown phenomenon of crema. They called it the foam layer “Schiuma”. A little later, the “Schiuma” was renamed “Crema” and people became aware of the aroma-protecting function of the crema. Since then, the crema has been an integral part of espresso.
Espresso beans with a great crema
Here you will find a selection of good espresso beans that we have tested and for which we can give a clear recommendation. Full crema guaranteed!
How does crema taste?
As nice as the crema looks on an espresso – this layer of foam is somehow not that tasty, because it tastes unpleasantly bitter. Before you drink it, you should stir the espresso to mix the extraction results.
The espresso is extracted in phases: first the acidity, then the sweetness, and finally the bitterness. By stirring, you can connect the phases and bring the drink into a harmonious balance between acidity, sweetness, and bitterness.
Alternatively, you can skim off the crema before drinking. This results in a purer espresso but lacks some body due to the skimming.
What should an ideal crema look like?
If everything went perfectly when preparing an espresso, then it should have a fine-pored, deep golden-brown crema without large bubbles or holes. After the crema has settled in the cup after the brewing process, it should be around two to four millimeters thick and not collapse too quickly (it should remain on the surface of the espresso for at least two minutes and only then disappear from the surface ).
The sugar test, with which the stability of the crema can be tested, is popular among experts: a small spoon of sugar is poured onto the crema. The test is passed if the sugar remains on the crema for a while and only penetrates slowly through the crema.
Another crema test is carried out as follows: a small line is drawn in the crema with the handle of a spoon. If the crema closes again quickly, the test is considered passed.
Is Crema too light? That’s it.
If the crema looks light and thin and has larger bubbles, there is an under-extraction of the coffee grounds. The espresso tastes flat and it lacks the silky, creamy consistency. The water flowed through the coffee grounds too quickly. The reasons for this are too coarse a grind, too low a brewing temperature, too old espresso beans, too little coffee grounds, and too little pressure on the portafilter machine.
Is Crema too dark? That’s it.
If the crema looks too dark and burnt (sometimes also reddish), there is over-extraction. The drawing of the crema surface is noticeably uneven. Light spots are between darker areas. The espresso tastes too strong, slightly burnt and bitter. The water ran too slowly through the ground coffee. The flow kept breaking off and the espresso slowly trickled out of the portafilter. The reasons for this are too fine a grind, too high a brewing temperature, too high a coffee dosage, and too high a pressure on the espresso machine.
From the coffee blog: Why the extraction rate is so important for the ideal coffee and espresso taste.
Not enough crema? That’s it.
The longer the beans have been roasted, the less carbon dioxide the beans contain. The older a coffee is, the less crema is created during extraction because the carbon dioxide has evaporated. A rich crema gives you the end result about the freshness of the coffee.
Crema & Coffea Canephora
Coffea Canephora (also called Robusta) plays an important role in coffee blends for espresso. Why? Due to the low oil content, Coffea Canephora is responsible for a thick and stable crema on the espresso. And a stable crema is usually a sign that the espresso is of high quality – at least from a visual point of view. A certain proportion of Coffea Canephora in espresso blends – usually between 10 – 40% – gives the espresso a firm and stable crema.
Conclusion on the crema
The crema tells you whether the coffee is freshly roasted and whether the espresso has been well crafted. From the crema, on the other hand, it cannot be determined whether the green coffee was of high quality and well roasted, or whether the machine was clean. And the last-mentioned points are indispensable for a good espresso. Therefore, the presence of a thick and greasy crema should not be rated too highly. Instead, focus on the taste of the espresso for evaluation.