What is the reason why espresso does not have fat? The right way to do espresso

The process of extracting full-fat espresso with a coffee machine is the romance of espresso players. Of course, it is also the daily work of contemporary boiler extractors. But one day the espresso suddenly extracted is not the same as usual, there is no oil, it is estimated that friends who encounter this situation for the first time will be very anxious, what is the reason?

Normally extracted espresso should be black espresso liquid covered with a layer of golden coffee oil about 1 beat 3 thick, which shakes like cream and feels like hanging on the wall.

In the normal state of espresso, if the coffee is extracted without oil, it indicates that there is something wrong with the coffee bean, the machine, and more likely the parameters and operation. Qianjie summarizes some possible reasons for your reference. The roasting degree of ① coffee beans is too light. Coffee beans sold on the market are usually divided into coffee beans for manual drip filtration and coffee beans for Italian coffee machines. The former is basically based on single beans, and the baking will be shallow. The latter is mainly blended (formula) beans, but also a single bean-based SOE, baking will generally be too deep.

Light roasted coffee oil effect: relatively thin, light yellow-white color generally speaking, the deeper the roasting degree of coffee oil performance will be more abundant. On the other hand, the use of hand-made single beans to make espresso will be thin, so you should be sure to buy it before you buy it. ② coffee beans are not fresh. If the extraction state of espresso is normal, then it is likely that the coffee beans are not fresh. Italian coffee machine extraction is actually quite hypocritical. When too fresh coffee beans extract espresso, the oil will be unstable, bubbly and decompose quickly; stale coffee beans have no oil. Generally speaking, the cultivation period of Italian coffee beans is about 7-10 days, that is, the extraction state of coffee beans will not begin to stabilize until the seventh day after the baking date. The taste period of Italian coffee beans is about 60 days. After two months, the espresso beans have little aroma and flavor, and the amount of fat will be greatly reduced. (nitrogen preservation in front street has not been tested only under normal preservation conditions.)

Coffee beans are not freshly extracted. Espresso oil is scarce. ③ coffee machine itself is not under pressure. This problem is more common in the home coffee machine. Usually we can extract the thick oil is the pressure of the coffee machine 9bar to press out the essence of coffee pressed powder. However, some small espresso machines do not have a stable 9bar extraction pressure, so they will not be able to produce thick oil. ④ coffee is too rough to grind. In this case, the oil will not be rich. This situation is very good to confirm, the state of the extraction process is that the flow rate of the coffee liquid is very fast, accompanied by the perforation spray caused by the channel, the coffee oil will appear light and thin. Espresso also tastes light. You can take 20 seconds as a criterion, if you extract twice the amount of coffee powder within 20 seconds, then it is very likely that the coffee powder has been ground.

The extraction process is a mess. ⑤, the water temperature is too low. Nowadays, many new coffee machines have the function of manually adjusting the water temperature. In general, the temperature of Italian concentrated water is about 93 degrees Celsius. If the temperature is too low, there may be no oil.

Another common occurrence in the household coffee machine is that it may take 10 minutes or more from turning on to heating the coffee machine, and it may take 10 minutes or more to extract espresso without heating it. It is very likely that the water temperature is not high enough to lead to the absence of coffee oil, and the taste of coffee tends to be tart.