Does coffee extraction 25 seconds include pre-infusion? What is the effect of pre-soaking?

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Prepreg can take many forms, from low prepreg to strong prepreg, to variable pressure and different time lengths:

-low / progressive pre-soaking: one is to use x-measure water to flow slowly and steadily into coffee pressed powder, stay for y periods, and maintain z pressure rather than full extraction pressure for pre-soaking.

-strong pre-soaking: one is to use x amount of water to quickly rush into pressed powder at full 9bar pressure, then stop the water for a period of time, and then boil water, using full pressure to extract coffee liquid.

Pipe pressure: a method of using the same pressure as the inlet pipe for the X amount of water, keeping it for a period of time, and then turning on the full pressure to extract coffee.

From the above definition, it can be inferred that prepreg has nothing to do with technology, and there are three main variables: injected water-X, prepreg pressure-Z, and prepreg time length-Y. All of these variables and different methods have different effects on espresso.

In addition to pre-soaking, espresso has more complex and experimental aspects. "flow state" or "pressure state" can be used as parameters to be adjusted in the next step of pre-immersion experiment.

As for the ideal pre-soaking time how to set? First of all, remember that extraction begins as soon as the coffee powder comes into contact with water, so the time should be counted from the first moment when the coffee powder comes into contact with water. As for the best way to soak and the overall time, it mainly depends on your personal preference and which flavors you want to avoid.

However, as to whether pre-soaking has a substantial effect on the taste of coffee, we have also done comparative experiments with coffee that has not been pre-soaked. After tasting numerous cups of concentrated coffee, we have come to the conclusion that:

5s pre-soaking: bright acidity and smoother taste, taste and flavor have better structure and layering

10s pre-soaking: bright acidity and mellow Body, with insipid flavor and shorter aftertaste

15s pre-soaking: slightly sour, more round Body with increased sweetness and flavor complexity

30s pre-soaking: sharp acid, more full-bodied Body, dry feeling.