How to judge the extraction quality of Espresso espresso?

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A perfect Espresso is really hard to come by. Making a good Espresso (espresso) is one of the most challenging "artistic activities" for both coffee lovers at home and a veteran Barista in a cafe. In addition to the most important taste, oil is probably the most commonly used criterion for judging the quality of espresso. Its color, evenness, thickness and fineness directly tell us the quality of a cup of espresso.

We should judge the quality of a cup of espresso from the following aspects:

★ flow rate determination

The flow rate of espresso directly determines the taste of Espresso, too fast flow rate will make the essence of coffee has not been dissolved into the water, but the water has passed through the coffee powder, resulting in coffee tasteless; too slow flow rate will make coffee essence and dregs all into the water, resulting in coffee with obvious scorching taste or exciting bitter taste.

For beginners, the flow rate control is a quantitative standard, generally we take 20 seconds to 30 seconds as an optimal value. The more advanced ones will judge the flow rate by the shape of the water flow when the coffee is extracted. Foreign baristas like to use the mouse tail to describe the flow rate of coffee. Anyway, the flow of water during extraction should not change suddenly, otherwise it will be obviously perforated, and there is no need to taste the next step at all.

The higher level is that the flow rate of coffee is determined by its taste. If the flow rate is faster, the taste will be single but refreshing, and the sour taste will be heavier; if the flow rate is slow, it will increase the mellowness, and the more complex but bad taste will be released at the same time. The bitterness will be a little heavier. The speed of the flow rate is a dynamic process, no barista or any kind of coffee equipment can guarantee the consistency of the coffee flow rate, and even the humidity of the weather will affect the speed of the coffee flow. So baristas must know that it is easy to control the flow rate rather than being controlled by it.

★ thickness determination

The thickness of Espresso grease is a very complicated problem, which is much more complicated than the color of grease. The thickness of the grease is essential for making a real cappuccino and the popular coffee flower, so the rich and long-lasting grease can be said to be an important sign of high-quality Espresso.

The grease of Espresso is not really a layer of "oil" floating on the surface of coffee, but is composed of delicate bubbles, so when we study the thickness of grease, we should not only look at how thick it is, but also observe how long it can last. The thickness of oil generally has a lot to do with the freshness of beans. If the beans are too fresh, the extracted oil will be very thick, but it will dissipate very quickly. We think that this kind of oil is too rough. Therefore, bean cultivation plays an irreplaceable role in the formation of oil. Only beans raised correctly can extract long-lasting oil. Although the fat is too thick is not necessarily a good thing, but if the oil is too thin, it must be a bad thing, generally due to: beans stored for too long or improper preservation; too little powder; grinding too coarse or too fine; extraction time is too long or too short; the flow rate is too large; improper filling pressure and other reasons. It is generally believed that one serving (1 ounce) of Espresso, the fat is more than 0.5cm thick and accounts for about the volume of ⅓, and the duration is at least 2 minutes or so is the embodiment of a high quality oil.

★ color decision

The color of Italian coffee oil can well reflect whether the extraction degree of Espresso is moderate, whether the powder is enough, whether the filling force is in place, whether the water temperature of the coffee machine is correct and whether the beans are fresh and many other factors.

The color of Italian coffee oil is preferably golden yellow and slightly brown, and the color of oil is milky white, which is generally called underextraction, while the preference for dark brown is excessive extraction.

[insufficient extraction]

The lack of extraction is generally reflected in the milky white color of the oil, which may be due to insufficient powder, too light filling force, too low water temperature, too coarse coffee powder, insufficient water pressure or not fresh coffee beans. sometimes it is also related to the light roasting of coffee beans or the variety of coffee beans.

[excessive extraction]

Excessive extraction is generally reflected in the dark brown color of the oil, which may be caused by too much powder, too much filling force, too high water temperature, too fine grinding of coffee powder and other reasons, sometimes it has something to do with the excessive roasting of coffee beans. The grease color of espresso is the most basic knowledge that coffee lovers and baristas must understand and master, which can help you understand the quality of coffee in the shortest possible time.

★ aroma determination

The perfect Espresso should have a pleasant aroma and should never have a scorched smell. If there is a burning smell, then unfortunately, you may be drinking a cup of over-extracted Espresso.

★ tasting decision

Espresso is the most fragrant coffee in the world. You need to drink a cup of water and embellish your mouth before tasting it. The basic tasting method is to smell first. Espresso has a strong and charming aroma and should be well immersed. Then there is the product, Espresso has a variety of genres, of course, according to personal preferences to decide. Basically, there are two kinds, one is to drink it in one sip, the other is to drink it a little first, and then drink it in one sip. There is a difference in the way and feeling of each taste. Basically, what you can taste in one sip is the comprehensive taste of Espresso, while if you drink it in different times, you can taste the stratification of Espresso taste. If you drink a perfect cup of Espresso, you must be able to feel the obvious and flamboyant difference between it and any other coffee you've had. The perfect Espresso can keep your mouth dry for 20 minutes and 30 minutes after drinking.

What on earth is coffee? A drink, a carrier of taste, a way to feel the details of life. Whether it's Espresso, American style or latte, when you spend dozens of hours in a cafe to enjoy a cup of coffee packaged by various cultures, remember to think about and learn to appreciate whether you drink a perfect cup of coffee, instead of spending dozens of yuan to drink "pot water", so that you always feel that coffee is bitter, coffee is not good, coffee interferes with sleep.

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