The extraction standard of espresso the traditional Italian formula and the different deduction of the extraction standard by SCAA

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Italian concentrated extraction judgment plays an important role in a coffee shop that pays attention to coffee quality, because Italian concentrated coffee is not brewed by hand, French filter pot, or siphon (siphon kettle). After brewing, you can take a sip to confirm the flavor and quality of the coffee, but it is the base of most coffee consumers' favorite drinks (such as latte, cappuccino, etc.). In addition to the right milk, Italian concentration with near-perfect extraction is also indispensable to drink a cup of cappuccino with excellent flavor, so Italian concentrated extraction depends on other reliable information to help baristas judge.

The rules for judging the extraction standard of the traditional Italian formula

The traditional Italian judgment rules are as follows: 8-10 atmospheric pressure, 7 g coffee powder, 86-90 ℃ water temperature, 25 ±2.5 ml single espresso extracted in 20-30 seconds, or 50 ±5 ml double espresso extracted with 14 g coffee powder at the same time and pressure, usually using the double shunt filter handle (double portafilter), which is common in most cafes. As long as the coffee obtained meets the above range, it is considered to be a cup of normally extracted espresso.

SCAA's explanation of espresso

Later, the American Fine Coffee Association (Specialty Coffee Association of America, referred to as SCAA) had a slightly different interpretation of espresso: the single espresso was extracted at 9-10 atmospheric pressure, 7-9 g coffee powder, 88-92 ℃ water temperature, and 45 ml in 22-28 seconds. However, in practice, it will be found that such data are only for reference, because there is a big gap between the roasting degree of coffee and the understanding of coffee flavor in the past decade. In the past, deep-roasted formula concentrate dominated the market, and espresso with an emphasis on nutty and cocoa flavor was very popular. If the water temperature is too high, the bitter flavor will be extracted, which is slightly different from the 93-94 ℃ used in today's light and light roasted coffee. Coupled with the rapid development of coffee machine manufacturing technology in recent years, coffee machines with variable pressure and emphasis on pressure curve (pressure profiling) have been invented, and the brewing pressure is no longer a fixed 9 atmospheric pressure, whether it is the introduction of prepreg pressure (pre-infusion) or mid-stage slow drop pressure extraction (gentle ramp out of pressure). All kinds of pressure curves that exceed the old rules have been tested and tested one after another. Even the same coffee bean has different flavor spectrum under different pressure curves.

The third Coffee Revolution affects the extraction of Italian concentrate

During the third wave of the Coffee Revolution, coffee people who advocated science-based extraction not only narrowed the reasonable scope of normal extraction, but also added a lot of criteria that could help judge whether it was good or bad. it was considered that in general, Italian concentrated extraction should use 18 g coffee powder, obtain a liquid weight of about 30 g, water temperature 92-94 ℃, and extraction time 25-27 seconds. It can be noted that it can be judged from the volume of coffee liquid to a more accurate actual weight of coffee liquid, this reason is that coffee due to brewing pressure, roasting depth, freshness and other factors will affect the amount of coffee oil (crema), if judged by volume, it is very unreliable. The water temperature also rose to 92-94 ℃ due to the shallower roasting of the third wave of coffee. In addition, the invention of the bottomless handle (bottomless portafilter) also allows baristas to observe the extraction of coffee throughout the process. If there are problems such as uneven extraction (uneven extraction), channel effect (channeling), and early whitening (blonde gusher), they can quickly remake a cup of coffee before serving it to the guests. Since I first came into contact with the espresso machine, I have been lucky to use bottomless handles to extract espresso, giving me the opportunity to observe the extraction of each cup of coffee, thus giving me a lot of opportunities to learn.

The next article will discuss common extraction problems and newly discovered methods to judge the quality of coffee.