Can you judge whether espresso is good or bad by coffee fat? What is the fat crema of espresso?

People often hear people say, "to judge whether espresso is good or not, just look at the fat." The best espresso oil is delicate, rich and golden. " Can the taste of espresso be judged by the state of the oil?

If you want to know whether this method is feasible, Qianjie only needs to give you two questions.

The first question, the picture below is only a cup of delicious espresso, please find out the good coffee according to the state of the oil.

The second question, the following picture is also only a cup of good espresso, please find that cup of good coffee according to the state of the oil.

The correct answer is the first question, the third cup, the second question, the second cup. I believe that many friends can choose the right question, while some friends can even guess the right question.

Looking at the grease state of espresso is like looking at the powder pit of hand-made coffee, you can't tell whether a cup of coffee is good or not, and the delicate and rich golden oil is not necessarily good. However, some possible problems can be judged from the state of the oil.

Let's start with what this golden coffee grease is. The oil of espresso is essentially the insoluble oil in coffee beans wrapped in carbon dioxide, both of which are derived from coffee beans. In fact, the golden foam on the surface of the powder layer in hand-brewed coffee is also oil and a small amount of carbon dioxide.

Due to the extraction pressure of the Italian coffee machine as high as 9Bar, the oil and carbon dioxide are pressed directly into the coffee, and because the oil is insoluble in water, it will be gradually delaminated to form a golden coffee oil.

Therefore, the quality of coffee oil mainly depends on the content of carbon dioxide in beans, the degree of grinding and the degree of roasting of coffee beans. Therefore, sometimes the state of the oil will reflect some problems. For example, the most common coffee oil is rich, but the texture is rough, decomposes quickly, and caking occurs. Espresso in this greasy state tends to have an unobvious flavor.

This is because the coffee beans are not ready, the state is too fresh, and the carbon dioxide in the body is too exuberant. As mentioned earlier, the oil richness of coffee has something to do with carbon dioxide. Coffee beans are very rich in carbon dioxide, and the oil pressed out will naturally be very rich. However, too much carbon dioxide will also make the structure of coffee oil unstable, easy to decompose and lead to large bubbles. When there are too many bubbles, they will pile up and become illiquid. Its state is very similar to that of milk foam.

Carbon dioxide is the protector of flavor, whether it is natural volatilization or artificial extraction, so the freshness of coffee beans will affect the extraction of coffee, so that the extracted coffee has no obvious flavor. The other extreme is that coffee beans are not fresh, naturally there is less carbon dioxide in the body, so the oil pressed out is very thin. If the coffee beans are not fresh, the espresso extracted will not taste good.

The second is the effect of grinding degree on the state of oil. For example, because the coffee powder is too coarse to effectively block the water pressure, the coffee liquid will flow very fast, the color of the oil will be lighter and the texture of the water will be thin. If this is the case, the taste of espresso will show acidity and water feeling. On the contrary, the coffee grinding is too fine, coffee pressed powder of the role of blocking water pressure is strong, then the oil will be very rich, sticky, dark color. If this is the case, the taste of espresso will show bitterness.

The factors that can judge whether coffee is good or bad by the state of oil is over, and then there is an example that you can't judge whether coffee is good by the state of oil. The first example is that a cup of espresso is extracted from a deep-roasted coffee bean and a light-roasted coffee bean respectively. The espresso oil quality of deep-roasted beans is bound to be richer, darker and Body better than that of light-roasted beans. But the two cups of espresso have their own characteristics and both belong to the category of good taste.

The second example is the second question asked in front of the street at the beginning. The three cups of fat all look delicate, rich and golden. But only one cup performed well. Because these three cups of espresso extracted by the pressure of 6Bar, 9Bar and 11Bar respectively, the coffee oil extracted by this range of pressure extraction will not change much, but the taste is obviously different from the taste. 6Bar will be more boring, a variety of flavors are not shown. 11Bar is the emergence of exciting, bitter taste.