The perfect crema as a guide to the perfect espresso – and it’s true!!!
This change of perspective makes one thing clear: a barista beware not so on the crema because they want the perfect coffee foam. He tries to create the perfect crema because they want the perfect espresso.
Only if all components of the espresso preparation play together optimally then and only then can an optimal coffee extraction take place, which is the reason for the optimal crema. But what does this optimum crema look like?
The basic rules of the coffee crema:
1. Hazelnut brown color with slight thinning
2. Stable at least two minutes
3. Solid structure without holes or bubbles
4. Sugar stays short at the top (sugar and not biscuit! 😊)
5. A slightly oily mouthfeel with a longer reverberation
You can really forget all so-called rules of thicknes. Because here every barista has his own opinion and of course it always depends on the amount of espresso and in which cup is landing. This article from the blog site The Spruce explains it very good.
None of the five above points can be considered alone, if we want to take it as an indication of the elements of the perfect espresso. Here’s a reminder of what makes an espresso almost perfect (technically):
1. Freshly roasted espresso beans in the perfect roast degree
2. Freshly ground coffee beans in very fine grinding (1 to 2)
3. Coffee powder quantity: 7 g
4. Water quantity: approx. 25 ml
5. Brewing pressure: 9 bar
6. Lead time: approx. 25 s
7. Brewing temperature: about 94 degrees Celsius
Even apparent trivialities, such as the proper slamming of coffee grounds in the filter holder or the flashing of the machine before the cleaning preparation, have an extreme impact on the result – and thus also on the “look and feel” of the crema.
What is wrong with the espresso (and the preparation), if the crema is wrong
I always find it interesting that every tiny error in the preparation of the espresso with a sieve carrier machine is so clearly reflected in the crema, although that does not mean that the espresso itself does not taste good.
But if something is wrong with the crema, that really increases enormously the possibility that the coffee is also rather medium (my opinion).
This, in turn, is due to the fact that the cream formation in the coffee cup is an integral part of the coffee preparation process.
I want to say here again, that all this has to do with the special interaction of all components in the coffee machine – and a bit of nanotechnology, chemistry and physics are also involved.
At this point we are much more interested in what typically defects the optic of a crema. Let’s take a closer look.
Normally we should always review the entire brewing process again.
The crema is unstable or decays very fast:
This feature usually indicates that the espresso is bottom-extracted. And that can have several common causes:
1. Grinding degree too coarse
2. Not properly dumped
3. Pressure too low
4. Beans too old
The fourth factor in particular is very important but is often overlooked by non-professionals. If you storage coffee beans in a coffee-box, they “exhale” carbon dioxide for a while after roasting. And at some time after this outgassing stops.
But as I mentioned above, carbon dioxide is essential for the cream formation. That is why old beans can no longer produce any decent crema after the end of a coffee oldening period.
The crema is missing:
This is actually a “no go” criterion for an espresso!
To have no crema!
If the crema is completely missing, you probably did a lot wrong. All that is needed is to re-adjust all the components, to clean the machine and to clean and preheat the coffee cups.
Quite often, a dirty machine can be the main source of error for missing crema, because it destroys during the process the connection of the coffee beans components, water and carbon dioxide.
The crema is too light or too dark:
Here, of course, it is a good thing to argue about what means too light or too dark. But in principle, all nuances that differ from the hazelnut color, are some kind of error message.
If the crema is too light (and corresponds roughly to the typical shading), this indicates a bottom extraction. If the degree of grind and bean age are correct, and if the crema itself is relatively stable, it is best to check the brewing temperature again, which is usually too low in this case.
I hope you like my little tips about the perfect coffee crema and you read more from my articles here in my CoffeeNation!