Coffee extraction theory of standard powder-water ratio SCA gold cup extraction of Italian coffee beans

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Espresso coffee extraction detailed steps Italian concentrated common sense

Many people asked about the espresso extraction rate related things, not very clear about the meaning of 18%--22%, drew a picture to add explanation

According to SCA's study, the maximum extractable rate of Italian coffee beans is 30%. Simply put, 10 grams of coffee beans can extract up to 3 grams of extract, and the other 7 grams (xylem) cannot be extracted.

In other words, of the 30% extractable espresso beans, about 6- 7 percent extraction is the most appropriate, that is, 18%-22% coffee.

Now let's do the following for the espresso extraction rate and the variables:

The finer the coffee powder, the higher the extraction rate. The coarser the coffee powder, the lower the extraction rate.

The higher the water temperature: the higher the extraction rate. The lower the extraction rate.

The longer the time, the higher the extraction rate. The shorter the time, the lower the extraction rate.

The above principles are basically the basic principles of brewing coffee. It seems easy to be true. It is good to simply use the coffee powder thickness. It is difficult for the bean grinder to grind exactly the same particles. Therefore, when the user adjusts the thickness of the bean grinder, the powder that comes out is basically fine and coarse. If each particle of powder is analyzed in the brewing process, it must be some excessive extraction and some insufficient extraction. Even if the final brew results in 18 - 22%, that doesn't mean it's a good cup of coffee.

Speaking of this, I guess some people will suddenly realize that 18--22% is not easy to imagine, the grinding of coffee powder may be a university question, before you have introduced coffee fine powder sifter, basically to solve the problem that too much fine powder will cause excessive extraction during brewing.

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