What should authentic espresso taste like?

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"I've figured it out! The same 18 grams of coffee powder takes 15 or 30 seconds to make one or two cups of coffee. The reason why they taste different is the roughness! "

After weeks of thinking, the guest finally figured out the "answer". Anyone who knows a little about espresso knows that adjusting the amount of powder and thickness is the basic law to control the flow rate. What he found is not only the standard complementary relationship of "adding powder when grinding thick, and reducing powder when grinding young", but also realizing the effect of adjusting the two on taste.

The understanding and pursuit of contemporary espresso (contemporary espresso) in the industry has jumped out of the traditional framework. Typical espresso, which emphasizes strong taste, oily taste and bitter taste, is often mixed with commercial grade Robusta beans with high caffeine content and deeply roasted. What the boutique tide advocates is the fresh extraction of 100% Arabica varieties, emphasizing rich layers and a balance of sour and bitterness. Once Cafe Sant'Eustacio, a famous coffee shop in Rome, asked the clerk how long the beans had been fried on the shelves. He asked, like an alien, "how long is it a question?" In short, we cook coffee according to traditional standards! "

It has been mentioned earlier that espresso is defined in terms of "time and capacity" (about 30 ml in 30 seconds) and "powder and capacity" (27.7 grams of liquid made from 18 grams of powder). But in fact, coffee cakes experience high pressure and high temperature in tens of seconds, and what happens under the microscope is far beyond what can be seen with the naked eye.

Coffee liquid is made by washing coffee powder with hot water. These include gases, water-soluble substances, and non-aqueous substances such as coffee oil. Will the volume and resistance of the coffee cake follow? The extraction process changes; for example, the release of gas will increase the resistance of pressed powder, but the other side, through hot water? Wash and dissolve, the distance between powder particles becomes wider, and the resistance will be reduced. In addition, the fine powder will accumulate as water flows from the top to the bottom of the cake, resulting in an increase in lower resistance. Simply repeating the combination of time and capacity is not enough to replicate coffee with the same taste.

Coffee cake cracks affect the taste

Want it? Good Italian coffee, the primary prevention channel (channeling): if there are cracks in an 18-gram coffee cake, according to the inertia of the water, it will flow away from the lowest resistance. So the coffee powder on both sides of the crack will be overextracted after a certain period of time, but the rest of the cake may not be wet through at all and become underextracted. So, despite making 27.7 grams of "standard coffee" with 18 grams of coffee powder, if there are cracks in the cake, it is actually used? It may be less than half cooked. What is more, the part of the crack that tastes bad becomes bitter due to excessive extraction. Therefore, the goal of opening the handle with the naked eye is to "let it taste what should be tasted, and stop when it is enough, regardless of whether it reaches the standard or not."

If espresso is an acid (A) bitter (B) balanced drink, then the ristretto with shorter extraction time is mainly acid (A), because the fruit acid has high water solubility and will be extracted first. On the contrary, excessive extraction is characterized by a taste similar to peanut ash (C). The ideal espresso is only A B, but in fact, a small amount of C is inevitable. Ristretto can be processed with the same coarse but short time to avoid the emergence of B; another method is to extract the coarser powder with a longer time. Local enthusiasts who are at the forefront have adopted this method to define espresso: even if it is only 20ml, we call it espresso profile. Is there an A, a C and a large cup? That is the ristretto that failed to extract.

It is more interesting to follow the sense of taste than to blindly conform to standards.