The Crema of the Crop
It Makes Espresso, Espresso
(above image used here with permission from www.EspressoMyEspresso.com)
Crema certainly is something special. “True” crema only is created when espresso is made. As seen above, it is a viscous ‘foam’ that floats above the espresso liquid. During the extraction of a two-ounce espresso nearly 100% of the beverage may appear as crema as the extraction ends. After that the crema breaks down and becomes the dark liquid espresso, but a good amount of crema remains floating on top.
The crema is a combination of a number of components. It is mostly a colloid, which by definition is a suspension of insoluble components mixed in with other components. Good crema takes time to settle out into a liquid. The insoluble component of this colloid are microscopic plant fibers from the coffee beans along with oils contained in the ground coffee. We have all seen the oils on the surface of dark roasted beans. All coffee beans possess those oils whether you see them on the surface or not.
Most of us know that coffee beans, once roasted, release carbon dioxide gas (and some other gasses). It is the release of these gasses that causes a bag or fresh roasted coffee to “inflate” or a storage jar’s lid to “pop” or “whoosh” when opened. Take the tiny bubbles of this gas which is released during the extraction process and mix it with the oils, plant fibers, water, and other trace components of the coffee bean and you get crema.
Why Just From Espresso?
There are two major factors that make the creation of espresso different from most all other methods. The first is the pressure used to create the beverage. No other method of coffee making uses 9BAR (about 135 PSI) of water pressure. A home water system normally has no more than between 40 and 60 pounds. Most espresso machines produce two to three times that.
The second factor is that the coffee is ground very fine with particle sizes held in a fairly tight range. The only common form of coffee making that uses a finer grind is Turkish. Now take that finely ground coffee and pack it very tightly into a little metal cup with lots of tiny holes in the bottom (the filter basket). Lock that into the espresso machine and force the high pressure water at about 198 to 202 degrees through it. The force and heat extract all those previously-mentioned components creating the crema and the espresso.
The Category is Beverages, and the answer is, “Crema Means Good Espresso.”
” ‘What is False?’ Alex.”
Crema is just a mechanical result of forcing hot water through coffee prepared as outlined above. We can say that if there is no crema on freshly-made espresso then that is a problem. No crema most likely means one of two things:
1 – Some of the necessary components did not exist in the beans for reasons such as :
- The beans were old and stale
- The beans were improperly stored
- The beans were of low quality to begin with
- The beans were not properly roasted
2 – The preparation method was lacking in some way, such as:
- Too low or too high of a brew pressure
- Coffee ground too coarse
- Water Temperature far too low
- Not enough coffee was used
- Poor water quality
So while crema can be a delicious component of espresso, depending on crema as a definitive indicator of the quality of the espresso is something that you learn is false very early on. I have personally been making espresso for well over a decade and can assuredly tell you that I have made some crema-topped espresso that caused me to feel sorry for the kitchen sink into which I had to expectorate the first sip and into which I then had to pour the rest.
If you find that crema on its own does not taste pleasant to you, try stirring it back into the espresso before sipping it. The combination of the sugars extracted which reside in the liquid below should combine with the crema to create a complex tasting beverage you can enjoy.