Judging Expresso Extraction by Crema

by Mauro Cipolla

By now, most espresso aficionados understand the importance of the presence of crema in each and every espresso extraction. That is good. Unfortunately, most people are too eager to express comments of joy relative to the quality of the drinks made, based solely on the presence of crema. That is bad.

Why is this bad? After all, if what we see floating on top of the demitasse is crema, that is the essence of the espresso extraction. That is the symbol of a great extraction and a good coffee. That is what we are all trying to achieve, is it not? A good question deserves a good answer. I am a supporter of the importance of crema in espresso extraction, but I also believe that there is more to a good espresso extraction than the mere presence of crema. In fact, I have personally tasted espressos that offered a beautiful looking crema, but were extremely acidic, astringent and undrinkable.

So the key to analyzing espresso extraction for quality is to go beyond the fact that crema is present. We must look at variables of the crema that are more complex and that better reflect the extraction process, giving true indications of what the resulting flavors may be.

The first task in determining whether a shot of espresso is indeed excellent is to look at the very first drop of the espresso extraction. Is the liquid dark, or is it crema? The first drop of a truly high-quality espresso shot should be crema. More drops of crema should follow the first drop and within two to four seconds of the first drop we should see a steady flow of crema. This flow should be consistent and continuous in both speed and in volume. The width of the flow should never be wider than one-eighth of an inch. The speed of the flow should be constant (it should not speed up as the volume of espresso extracted increases) all the way through the espresso extraction.

Next, we must look at color and consistency. The color of the crema should be medium brown. At this point, it should not be yellow, white, or tan to white. The flow should not have a lot of air bubbles, and should be as viscous as possible. As the crema flow starts layering itself on the bottom of the demitasse cup, it should not disintegrate or separate. It should simply remain a syrupy consistency, and should begin layering.

After about one-half to three-quarters of an inch of crema has accumulated in the bottom of the cup, you should see the crema change to a lighter, off-white color. It is just before this point (which should occur at 25 to 30 seconds from the push of the button for espresso extraction) that the flow should be stopped, since any more liquid allowed into the demitasse equals more acidity and bitterness.

Now, inspect the thickness or body of the crema. After the extraction, the crema layer (as inspected from the side through a glass demitasse) should settle slowly to between one-eighth of an inch to one-quarter of an inch in vertical thickness. This crema stratus should remain intact for at least a couple of minutes, and should be able to hold afloat two teaspoons of sugar for a few seconds. When looking from the top, one should see a uniform layer of crema with little or no air particles. There should be no dark ring of color on the outside of the crema's circumference, and there should be no white spots in any portion of the crema bed. The presence of large white spots anywhere within the demitasse or in the middle of the crema layer indicates a serious extraction problem.

Mauro The best crema is uniform in presentation-an even, homogeneous layer of color and texture. Should you ever encounter a crema with all of the above variables in place, but with a foul or unfavorable flavor profile, you can rest assured that you have done a fine job in setting up, maintaining and fine-tuning your equipment. Unfortunately, you may have a serious problem with your espresso blend of choice! Back to the drawing board....

Mauro Cipolla is vice president of Caffe' D'arte, a specialty coffee roasting company in Seattle, WA. He can be reached at (206) 762-4381; darte@ix.netcom.com .


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