The Crema,
what is it?
In the search for your coffee, this is one of the criteria that comes up the most when you ask us. You want a good coffee, that tastes like coffee, and that makes a nice"foam" on top. This famous"foam" is called crema, the term foam being reserved for beer. The word "crema" is Italian and therefore refers to the natural caramel-colored layer that forms on top of your coffee during the extraction of an espresso.
But what is it exactly? How does it form? Can you get it with all coffees and all machines?
This article is here to answer your questions!
What is crema?
Crema is made up of tiny bubbles that appear as a dense, creamy caramel-colored foam. The phenomenon that triggers its appearance is simple. To prepare an espresso, water is circulated under very high pressure. This dissolves more carbon dioxide, the famous gas produced during the roasting of coffee. When the brewed coffee flows into your cup, it returns to normal atmospheric pressure. Since it can no longer cling to the CO2, it turns into micro-bubbles. These tiny air bubbles combine with the soluble oils of the finely ground coffee beans to create an emulsion, the crema.
3 elements to respect to have crema
"Yes, but how is it that we are not guaranteed to have a beautiful crema with each espresso" you may ask. Well, you have to respect some factors to achieve this, three more precisely, that we will detail below:
- The machine used
It may seem obvious to some, but you can't get a good crema with every type of machine, and therefore with every type of infusion. The best crema is obtained with a manual machine, even if some automatic machines like the Jura can give good results. But the extraction process of a manual machine is more suitable, since you have control over the brewing pressure. A higher pressure, as explained before, will generally create more crema on your coffee.
So you won't get a nice crema with a Bialetti Italian coffee maker or a Chemex, which are manual brewing systems.
- The freshness of your coffee
We've mentioned this several times already, so you know it, but we'll repeat it for the sake of argument :D
A freshly roasted coffee is the guarantee of a good coffee in a cup. Well, it's also a factor in guaranteeing you a nice crema. And the explanation of why is simple: the longer you wait between the roasting date and the brewing date of your coffee, the less carbon dioxide (CO2) the beans will contain, this gas coming from the roasting process as explained above, since it evaporates with time (hence the valves on the coffee bags that allow you to let out the CO2 released by the beans). You will therefore obtain much less crema.
On the other hand, if your coffee is too freshly roasted, it will still contain too much CO2. The ideal is to wait at least one week after roasting to start your infusions.
- Roasting and the grind used
The roast of your beans will play a big role in your espresso extraction, and therefore in obtaining a nice crema.
Light roasts, for example, are not recommended for preparing an espresso because of the very short extraction time. The bean does not have time to develop its full body and aroma. The result is a very unpleasant tasting espresso.
The more oily a coffee is, the easier it will be to obtain a nice crema. Dark roasts are therefore easier to work with.
As for the grind, it must obviously be perfectly adapted to your machine to guarantee the best extraction and thus favor the creation of a beautiful crema.
Good crema = good espresso?
A "good" crema can be recognized by its aesthetic aspects. It is supposed to be smooth, with a good balance of colors, and to last over time. Ideally, a crema should last at least 2 minutes before fading in your coffee. It should represent about 1/10th of your coffee, without being too thick or too thin, and not be grainy in the mouth. As for color, the darker your crema, the stronger your coffee will be.
It is important to know that a good coffee can give a bad crema, just as a bad coffee can give a very good one, so it doesn't all depend on the quality of your coffee.
Our advice is to focus only on the preparation of a good espresso, the crema will then come by itself.
