What kind of coffee is espresso? How does the espresso coffee machine do espresso?

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Since Starbucks entered China, words like "espresso" can be seen on the streets. What exactly is espresso? What does Espresso espresso mean? Here to explain for you, let you have a little more understanding of Espresso!

In fact, espresso has been mentioned in the previous article, that is, coffee drinks based on Espresso coffee, including lattes, cappuccinos, macchiato and Campbell blue drinks. (strictly speaking, a latte should be Seattle-style coffee, while a latte in Italy only means pure milk.) so to understand espresso, you need to understand what Espresso is. In the Italian impression, Espresso is a kind of dark drink in a thick, small cup covered with red foam (crema), which is less than 50cc (domestic players like to describe it in red, that is, brown close to the appearance color of almond beans). Nearly 50 million cups of Espresso are consumed worldwide every day, and its aroma and taste are important irritants in the morning.

Espresso means express, which means fast (here it doesn't mean express delivery), that is, to order a drink that is ready to drink. There is a saying that "the consumer, not the Espressomust wait" means that it is the consumer who needs to wait, but the Espresso should be drunk immediately after it is made, and you can't wait for someone to drink it. Because after the Espresso is made, there will be a layer of "crema" on it, so you must drink it before the crema foam dissipates, otherwise it will lose its smooth taste, and the sour taste will gradually increase over time, as well as an unbalanced salty taste. Of course, some players like to wait until Espresso is cool before drinking her cold taste, because the tongue has different taste sensitivity depending on the temperature.

Espresso is also very different from other cooking methods, and a very important element is stress. In the early 20th century, in order to provide guest coffee quickly in a short period of time, a method was developed to increase the pressure of boiling water, that is, to put the water in a sealed heating pan and bring it to a boil. at this point, the pressure generated by water vapor can accelerate the efficiency of coffee extraction (the same principle as the current mocha pot). However, there is a disadvantage of this approach, that is, there is no way to extract coffee at the correct temperature (about 90 ℃ of water), causing boiling water to scald the coffee powder and produce a bitter taste. So another way to generate stress was developed, that is, using the coffee bar maker's arm to create pressure, resulting in an Espresso with crema (later with springs to provide more stable pressure than the arm). Today, most coffee machines use electric pumps to provide labor-saving and stable pressure to extract coffee.

Another important characteristic of Espresso is the extraction time. By using pressure extraction, Espresso can efficiently bring water-soluble and fat-soluble substances to the cup at the same time, the best average time is about 30 seconds, less than 15 seconds of extraction will result in weak and unbalanced sour coffee, more than 30 seconds will get stinging, bad-tasting coffee.

Therefore, Espresso has a quantitative definition. Espresso is a small amount of coffee (Italian espresso is a small cup of concentrated brew prepared on request by extraction of ground roasted coffee beans, with hot water under for a defined short time.) extracted from ground roasted coffee beans by hot water at a specific time.

The ranges of some of the related parameters are as follows:

The dosage of ground coffee powder is 6.5 ±1.5g.

Water temperature: 90 ±5 ℃

Injection pressure: 9 ±2 bar

Extraction time: 30 ±5 sec.

Coffee portion: 15: 50 ml, the best 25~30ml (according to the personal preferences of consumers or coffee bar operators)

This is the definition of Espresso. In the future, if you order a cup of Espresso in a cafe and see coffee with only 30cc, please do not beat the table and say that the boss cheated the money.

Part of this article is extracted from the book "Espresso Coffee, The science of quality".

Definition of Espresso:

Espresso is a brew obtained by percolation of hot water under pressure through tamped/compacted roasted ground coffee, where the energy of the water pressure is spent within the cake.

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