How to calculate the extraction time of coffee? Should the espresso extraction timing be when the coffee maker is started or when it is discharged?

No matter it is Italian style or hand impulse, the problem of time measurement will always trouble some small partners. For example, when making hand-brewed coffee, should the time be calculated before steaming or after injecting water? Or, when the extraction is concentrated, should the time be calculated before pressing to start the extraction, or should it be after the coffee comes out?

Although there is only a few seconds of jet lag between the two, but for coffee extraction, this is a variable to be reckoned with, which is why many friends are troubled by it. So, let's share from the front street where the extraction time of coffee should be measured and why time is so important!

When should the extraction time be calculated? The measurement of extraction time is actually easy to understand. The so-called extraction is to use water as a solvent to extract the flavor substances from the coffee. So, the moment the water touches the coffee powder, the extraction has already begun! The steaming water of hand-brewed coffee and the extraction of Italian coffee machine start, both of which need to press the timing button at the beginning.

Otherwise, when the water is stuffed, or the liquid is concentrated at the beginning of measurement, it will cause a time error of 7 to 8 seconds. The appearance of this error will definitely cause a great deviation in your judgment of extraction.

Why is time so important? Because time is also a kind of extraction parameter, it can also determine the extraction efficiency. However, the extraction time of coffee is not a directly controlled unit of measurement! What do you mean, for example, grinding, water temperature, pressure, water injection and other extraction parameters can be actively controlled by ourselves. If you want the water temperature to be high, let the water temperature be high, if you want to make the extraction pressure high, then the extraction pressure can be high, and so on.

The time is different, we can not directly control it, but need to adjust other parameters in order to control the extraction time. In other words, when you can accurately control the extraction time so that the gap is not too large, it means that the other parameters you use are reasonable and stable. Because to put it bluntly, the extraction time is actually the time it takes for water to pass through the coffee powder. The higher the resistance of the coffee powder bed, the more difficult it is for the water to pass through, and without the help of external force, it takes more time for the water to seep out completely. And that's why time is so important. it's the only parameter that can quickly find out when something goes wrong with the taste.

Take the example of hand-brewed coffee: the taste of this cup of hand-brewed coffee is a little underextracted, so what leads to this situation must be the inefficiency of extraction, which makes the hot water unable to fully extract flavor substances. There are so many parameters related to the extraction efficiency that it is difficult to judge which parameter has gone wrong. In a case like this, we can quickly find the problem by observing the time used in the extraction. In the former street, for example, the hand extraction time of 15g coffee beans set in Qianjie was 2 minutes. If the extraction time of this cup of underextracted coffee is less than two minutes, then it may be caused by grinding and water injection; and if it is more than two minutes, then it may be caused by insufficient water temperature and insufficient stirring strength (which can be classified as manipulation).

The same is true for the extraction of espresso. When the pressure, water temperature and water output are all fixed, the only thing that can change the extraction time is the amount of powder and the thickness of grinding. So when there is a deviation in the taste of the extracted coffee, we will adjust the amount of powder or grinding thickness according to the extraction time. Therefore, time is a very important parameter. Finally, Qianjie would like to mention one more point: the reason why espresso does not come out immediately during extraction is because of the great resistance formed by pressed powder (including the release of carbon dioxide). It takes some time for hot water to seep out, even with the help of pressure. The moment the coffee machine starts the extraction, hot water has actually come into contact with pressed powder, whether it's pre-soaking or conventional extraction. So the time point of the extraction of espresso is the same as that of hand brewing, and it has to start synchronously at the beginning.

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