How much coffee powder does espresso need, and how to evaluate the taste and flavor of espresso?

First of all, let's understand what espresso is.

Espresso refers to grinding very fine coffee powder, using high temperature hot water and high pressure to extract a small amount of coffee in a short time, probably using a water temperature of about 90 degrees, plus a pressure of about 10 Pa, rapidly extracting about 25 milliliters of espresso.

Espresso (Espresso) is a type of coffee with a strong taste by using hot water of 92 degrees Celsius and a pressure of about 10 Pa to rinse through the ground fine coffee powder. It was invented and developed in Italy and began in the early 20th century, but until the mid-1940s, it was a drink made separately through vapor pressure. After the invention and successful commercialization of the Spring Lever (spring piston lever) coffee machine, espresso was transformed into a drink known today.

At that time, the original purpose of this coffee machine was very clear: to make coffee in a short time. The word "Espresso" also means "Espress". That year, an inventor named Luigi Bezzara from Milan, Italy, registered a patent for the invention, which was described as a "machine with a detachable handle and a detachable head group that can extract coffee at high pressure in a short period of time." Since then, the production method of coffee has changed completely, and "high speed and convenience" has become a brand-new fashion standard for coffee shop service. After the patent was bought by Desidero Pavoni in 1905, La Pavoni designed and produced the world's first commercial espresso machine: The Ideale. However, from the point of view of modern technology, the design of this coffee machine is not reasonable. The temperature of the head of the coffee machine can reach 140 degrees, but the pressure is as low as 1.5 bar, which is completely unable to compare with the 9-bar pressure coffee machine we use today. because the pressure is too low, the coffee extraction process lasts as long as 45 seconds. the taste of the coffee is very different from today's espresso, but somewhat similar to the bottom filter coffee.

How to determine the amount of powder concentrated in Italian style?

We can first observe that the filter cups of our machines are more or less different in shape and capacity due to different brands. Generally, the common filter cups can be divided into wide caliber and narrow caliber, while the caliber is 53mm, 55mm, 58mm and other sizes. Usually the narrow caliber filter cup is deeper, and the caliber wide is relatively shallow. This difference is mainly affected by the cooking head design of various coffee machine manufacturers. But the amount of coffee powder that can be filled in each filter cup will be the same.

The same caliber filter cup can be divided into single (single) and double (double) types. The amount of powder that can be filled in a single part is about 7-8 g, and that in a double part is about 16-18 g.

So how to evaluate the taste and flavor of espresso?

First of all, we can look at its aroma and take a closer look at the aroma of espresso. Then we can take a sip of it, from the sour taste, sweet taste, bitter taste to try, in the process of drinking, we can feel its heavy feeling, simply its weight on the tongue, consistency, and then we can feel its flavor, flower or nut, or caramel, and so on. Finally, evaluate its degree of balance, whether there is too prominent feeling, or inadequacies.