How many milliliters of espresso espresso per serving of espresso? how much oil can be produced in espresso?

Professional coffee knowledge exchange more coffee bean information please follow the coffee workshop (Wechat official account cafe_style)

Espresso coffee, to put it simply, is a process of extraction, in which all kinds of substances in the coffee are taken out as much as possible, and some are not at all, and then there is a good-looking appearance, that is, a thin layer of coffee foam floating on the surface of the coffee.

The reason why coffee has coffee foam is a very interesting physical phenomenon. After a certain temperature of water moves through an obstacle, a low-pressure area will be formed behind the obstacle. The water will boil in the low-pressure area. After boiling, fine foam will appear, and whether the foam can be maintained depends on the oiliness and concentration of the coffee. This process is endothermic, similar to that in refrigeration, where freon ejects, the pressure drops, and then it boils and vaporizes, and the principle is the same. The small water channels in the coffee pressed powder are similar to the capillaries in the refrigeration system. Well, if you have studied refrigeration engineering, please supplement it for me. (making coffee is the same as repairing air conditioners.)

From the sensory perspective of the Espresso, the wettability is obviously stronger than the bad, in vernacular, it looks very sticky, very hanging cup. In fact, it is very simple, that is, the concentration is very high, as far as forger products are concerned, about 33g a cup of espresso, which can dissolve about 0.5g of various ingredients. (very simply, weigh the cup before beating the coffee, weigh it again, and then air-dry the cup at room temperature. (a large part of it is oily. This, compared with all chain coffee shops, should be at least 0.1 grams higher, do not underestimate this point, the difference is very big.

The concentration of coffee is high, it is easy to get, just raise the water temperature, but caffeine dissolves less in water below 91 degrees, but when it exceeds 91 degrees, it will dissolve in large quantities. When the temperature increases, the taste of coffee will not be good, so it will not work. (it has to be mentioned here that McDonald's coffee scalded the old lady's lawsuit, and Mai Ji paid quickly because of the entanglement, which caused the problem of McDonald's raising the water temperature to increase the concentration. However, in China, Maiji is still the most conscientious industry. In terms of taste, basically, the lower the temperature of the water, the better the taste, why the coffee is best brewed with Santo Peiru mineral water and mocha pot, nothing else, the water temperature is lower than the coffee.