Is espresso decaf? how to drink espresso correctly?

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Espresso is an Italian word that refers to coffee that is quickly extracted by a coffee machine in a short period of time. It is the basis of almost all fancy coffee and a must-have in Italian cafes all over the world. Espresso is very small cup, usually only about 30 ml, the taste is very bitter, the surface is floating with a thick layer of grease, will be served with a glass of water at the same time, you can choose to add sugar. Guests who order Espresso in the cafe are either real coffee lovers who want to taste the most authentic taste of coffee, or simply because they are extremely sleepy and in urgent need of refreshing.

Oil is the golden or chocolate liquid that has just been extracted from the upper layer of espresso; after extraction, the lighter oil floats on the upper layer, while the darker coffee liquid stands still in the lower layer.

Concentrated oil is a mixture of a variety of substances: water extracts soluble substances from coffee powder at high temperature and high pressure, a process that emulsifies the natural oil in coffee and mixes the air to form tiny bubbles. At the same time, fresh roasted coffee itself releases a certain amount of carbon dioxide, and these gases are also involved in the above-mentioned emulsification reaction; the more freshly roasted coffee, the more carbon dioxide it emits. so we can also see large bubbles gushing out during the extraction process.

On the one hand, oil reflects the status of raw coffee beans, the more oil, the more natural oil content of coffee beans, which is also related to the handling of raw beans; at the same time, it also reflects the roasting degree and freshness of coffee beans. Of course, some people think that concentrated fat tastes good, but it's not absolutely true-Robusta's fat, for example, is beautiful.

Freshly brewed espresso will be covered with a beautiful golden crema, and crema will be produced when the ground coffee is extracted under 7-9 bar pressure.

Crema consists of the oil of coffee itself, although it is often defined as an indicator of good quality espresso, but it still depends on the characteristics of the bean itself. For example, washed coffee usually produces less crema, so crema cannot be used as an absolute basis for quality.

That said, crema is certainly visually pleasing and customers will like it, but you can't get crema if you don't have enough pressure to extract it.

Espresso generally uses mixed beans, and Robusta beans are generally used. Because of their high caffeine content and general flavor, commercial coffee beans contain more Robota beans in order to reduce cost. so the extracted espresso has a high content of caffeine and is used for refreshing.