How to use a semi-automatic coffee machine to make espresso? When you use a semiautomatic coffee machine to make espresso extraction,

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How to use a semi-automatic coffee machine to concentrate? What is the extraction time of espresso with a semi-automatic coffee machine?

Espresso has always had a very high status in the hearts of coffee lovers, not only because of its rich taste and pure Italian origin, but also because Espresso is not only a test of skill for baristas, but also a knowledge and love of coffee.

Hydraulic pressure

Modern coffee machines are much more advanced than early LAVA machines, with a water pump to control the amount of water and controllable water pressure. Espresso ideal water pressure is generally 9 BAR, which is generally recognized as the most ideal air pressure. The pressure of the boiler is related to the water temperature of making coffee and the impulse of steam. The higher the boiler pressure, the higher the water temperature and the greater the impulse of the steam; otherwise, the lower the water temperature, the smaller the steam. The boiler pressure is generally around 1 BAR, but there is still a lot of controversy about this number, and every barista has a different understanding. Water temperature depends on the needs of different varieties of coffee beans, some are subject to boiler pressure, some are more flexible and precise setting. According to the experience of most baristas, the water temperature is between 90 and 92 degrees Celsius, each barista can flexibly adjust according to their own understanding and needs, and can make their own style Espresso with their own hands. Packing force has various styles of packing. In this world, almost no two people's packing will be the same. Generally speaking, if it is heavy pressure, the required pressure will be the pressure like 25kg/m2, but packing is indeed the freest parameter in the golden rule.

Coffee bean grinding thickness

The grinding thickness will be related to many factors, such as climate, coffee bean baking degree, freshness, humidity, new and old ​​ of the bean grinder, and so on. There has always been a saying in the industry: "the right thing is that the grinding thickness is changing, and the wrong thing is that the grinding remains the same." The amount of Espresso powder for a single serving is 8 grams of coffee powder for 7 Murray, and 16 grams for a double serving. Extraction time the extraction time of the Espresso gold rule is between 22 and 28 seconds, but the extraction time is actually a comprehensive expression of packing pressure, powder quantity and grinding degree, which needs to be adjusted by the barista's understanding of Espresso. Extraction quantity Espresso single 30cc, double 60cc ml extraction amount almost no one will change, except for a few Italy will use a single serving of coffee powder but only extract 15ml coffee liquid coffee oil coffee oil complex can not be clearly explained by me in a few words, to put it simply, it requires a rich golden brown oil to be a good Espresso.

What is coffee fat layer (Crema)?

The coffee fat layer is a layer of coffee foam with rich taste and aroma floating on the coffee. To put it simply, when the air combines with the soluble fat in the coffee during brewing, the coffee fat layer is formed. Some people will call this phenomenon the Guinness effect phenomenon because it has a similar foam layer to the famous Irish black beer (stout).

An espresso with a clearly visible coffee fat layer requires good quality, moderately ground coffee beans and a skilled barista. Compared with dripping coffee drip coffee, the coffee fat layer gives espresso a more saturated flavor and a stronger finish.

What is the perfect coffee fat layer?

Each barista has his own idea of the definition of the perfect coffee fat layer. When brewing an espresso, the top layer of coffee fat should not be too thin or too thick, and it can be kept in a state for about two minutes.

Trying to get out of a beautiful coffee fat layer is a bit complicated, because there are too many factors that affect the results. However, there are several main points that can be followed in practice:

Too much coffee fat layer can lead to a decrease in espresso. Many baristas pursue a coffee fat ratio of about 1/10 of the whole cup of coffee.

Both excessive extraction and insufficient extraction will affect the formation of coffee fat layer.

If the coffee fat layer defoams within a minute, it means that the extraction time is too short, or the coffee beans are roasted too lightly.

Generally speaking, the extraction time of a good espresso machine is about 15 to 30 seconds, but each machine is different.

Remember to warm the machine before brewing coffee and clean the machine regularly to ensure the quality of operation. A dirty coffee will add bitterness to the coffee it brews.

Factors affecting the formation of coffee lipid layer

In fact, it is difficult to fully master the coffee fat layer, because in addition to the technology that practice makes perfect, it can also be affected by the following reasons:

How fresh are the coffee beans used for brewing? Fresh coffee beans produce more coffee fat because they still release soluble fat. Try to observe that if the nearby coffee shop uses self-baked beans, the espresso made by the nearby coffee shop is more likely to have a thicker layer of coffee fat than other businesses that do not use self-baked beans.

The roasting degree of coffee beans will also affect. Generally speaking, the deeper the baking, the less the coffee fat layer. Because a large amount of coffee oil has been released during roasting, coupled with stirring, packaging and grinding, coffee oil is more worn out. In addition, coffee beans that are too lightly roasted are not ideal. As a result, many coffee makers offer products that are roasted at a specific degree and specially used to boil espresso to ensure that coffee beans have enough oil.

The handling of coffee beans should also be taken into account. Sun-dried coffee beans usually flush out the best coffee fat layer because of their high oil content.

The cooking method of the espresso machine at home is also one of the factors. Many household machines have the function of automatic brewing, which is very convenient, but compared with the manual way, automatic setting will limit the production of coffee fat layer. In order to make up for this deficiency, some machines will rush out of the mimic coffee fat layer separately.