What causes coffee cake sticking to brewing head? Will powder cake suction in water separation net affect espresso coffee?

A few days ago, the street shared the "reason for the stagnant water on the handle of coffee", and a friend came to ask "what is the reason why pressed powder stuck to the brewing head after the coffee was extracted." Therefore, Qianjie came to talk about why this happened.

Too much powder is the easiest problem to find and the one with the least impact. Qianjie said that ideally, there would be a slight gap between the surface of pressed powder and the powder net on the brewing head, and when the coffee pressed powder is wet during extraction, it will expand slightly. If there is a large amount of powder, after buckling the handle, the surface of pressed powder will be in direct contact with the powder water net, and at the end of the extraction, the cooking head will absorb the excess water, which will easily make the pressed powder stick to the cooking head.

However, too much powder does not necessarily stick to it. Usually, pressed powder sticking to the cooking head has something to do with the amount of powder, but the probability of directly causing this phenomenon is not very high, about once every 10 times. The fresher the coffee beans are, the more likely they are to stick to the head because of the more powder. -take off the handle after a period of extraction is the most prone to the phenomenon of pressed powder sticking to the head of brewing. At the end of the extraction, if the handle is not removed immediately, the pressed powder will stick to the powder net to dry the water and slowly stick together.

The large amount of powder coupled with the failure to remove the handle on time after extraction makes it very easy for pressed powder to stick to the cooking head. As long as the extraction parameters are reasonable, the occasional adhesion of pressed powder to the brewing head will not affect the flavor performance of espresso. If this happens frequently, then it is better to reduce the amount of powder and adjust the parameters. Just as the amount of powder used in Qianjie is a little more than the capacity specification of the powder bowl, if you put the handle on the cooking head and take it off 10 seconds later, the hot and humid powder net will absorb some of the coffee powder.

Therefore, when buckled with the handle, pressed powder and powder water net contact, if you do not start extraction, pressed powder surface will be high temperature "scorched", resulting in a scorched taste. However, if the extraction key is turned on immediately after buckling the handle, there will be no abnormal flavor. When pressed powder is knocked loose, there is also a phenomenon that at the end of the stage of cloth powder and pressing powder, it accidentally knocks on the button before boiling the head, resulting in a gap between the pressed powder and the powder bowl directly. Similarly, when the amount of powder is relatively large, it is easy to be glued to the powder net. This situation will have a channel effect because the pressed powder is not close to the powder bowl, which affects the performance of espresso.