Precautions for using the espresso machine! What are the must-do elements before espresso extraction? Why do we need to put water in before espresso extraction?

Although the process of making espresso looks very simple, there are a lot of details that need to be paid attention to in practice. This is a passage often mentioned in Qianjie. Indeed, such as how to distribute the coffee powder evenly when distributing the powder, how to apply force evenly when pressing the powder, or how to dispense a qualified milk foam, all need to be achieved through attention to details. Then when it comes to the extraction process, we need to pay more attention to the details! But among them, there is one action that many friends still do not understand, and it is an action that the old master must emphasize when teaching, that is, empty hot water before extraction.

The specific operation is that before we put the handle card on the boiling head, open the water valve to release hot water for a few seconds before we can start the extraction of espresso. The reason why many friends are confused is that what is the meaning of doing so? In fact, the answer is very simple, there are two points, one is a well-known reason: wash the head! After we have extracted the coffee, some coffee grounds will get stuck in the filter of the brewing head because they come into contact with the brewing head or because of the reverse suction of the coffee machine. Even if we wash after extraction and concentration, it is inevitable that there will be some residues. Therefore, the release of hot water before brewing helps to make the water distribution network cleaner, so that the extraction will not be affected by the residual powder.

Another reason is to make the extraction of espresso more stable, and the taste of the extracted espresso may change unexpectedly without pre-release of water. You can take a look at the experimental comparison under the front street!

The experimental comparison is also using 20g powder to extract 40ml coffee liquid, the difference is whether there is a pre-discharge of water before putting the handle card on the head. At this time, the coffee machine has not been used for more than 30 minutes, so the gap between the two can be more obvious. Don't ask why the coffee machine can not be used for more than half an hour, but there is no one! )

After the extraction, Qianjie tasted two cups of espresso respectively. It was then found that the unwatered espresso was sour and slightly lighter (by comparison) than the watered espresso, while the watered espresso tasted more full-bodied and more balanced. Then, in order to ensure that the taste of Qianjie was not wrong, a coffee concentration meter was specially used to measure the extraction rate of coffee, and the results were 20.44% and 21.07%, respectively.

Although there is little difference in the numerical value, we can still feel a quite obvious difference in the taste. Then why is there such a gap? The reason is simple because the temperature of the water used in the extraction is not consistent. (the former also has the effect of pressure instability)

Why release water in advance? As Qianjie said above, in addition to cleaning the stains of the water distribution network, another purpose of pre-releasing water is to make the extraction of the coffee machine more stable. There are two main reasons for the instability of extraction, and different machines produce different conditions: one is that when the coffee machine is not in use for a long time, the temperature of the head will cool because there is no hot water to soak. If at this time we directly clip the handle to extract, then the hot water flowing out will be absorbed by these cooler pipes, resulting in a deviation in the extraction; the other is that the water in the boiler is stationary for too long, resulting in a higher temperature than the set target. Well, when we directly use this water for extraction, coffee is prone to over-extraction.

Not only the former machine and the present household machine, but also the commercial machine with better performance is also prone to this kind of situation. Therefore, in order to ensure that the various parameters during extraction and concentration can be more stable, coupled with the accompanying cleaning effect, the behavior of pre-discharge of water is quite necessary.

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