Principles and rules of Coffee extraction-what is the taste of excessive coffee extraction

Principles and rules of Coffee extraction-what is the taste of excessive coffee extraction

The data given by the general online or book materials are mostly (per person) 7 grams of powder, 15mur20 kg of filling strength, the method of operation is to directly load the powder, install it level with the edge of the handle, scrape the powder with a 45-degree angle with the top cover of the bean grinder, fill the pressure, get on the machine, and the extraction state (under the general temperature and humidity environment, fresh coffee beans) is very fine and stable in the first ten seconds, and the liquid is dark brown. The 12-second flow pattern suddenly thickens and speeds up the flow rate, about 15 seconds 30cc. Such a cup of esptesso is failed, the early extraction will be excessive, the scorched taste is quite obvious, the later extraction is unstable, the taste is messy, there is less oil, and even extreme bitter taste. Such a cup of coffee can be regarded as full of miscellaneous flavors!

Many people will think that it is due to the lack of powder pressing and the breaking of pressed powder. If we carefully analyze what happens in the handle of espresso extraction, I believe you will reconsider whether you should only work on the power of powder pressing!

As we all know, there are many factors that affect espresso. My analysis means that under normal circumstances, do not dwell on the details.

First of all, let's talk about what's going on in the coffee handle. In this way, after pressing the coffee powder, because the coffee powder is solid, the water will accumulate in the gap between the brewing head and the coffee powder, resulting in the early extraction flow rate is too fine, resulting in excessive extraction, and the coffee powder will automatically expand when hot water passes through the coffee powder. the position of the powder will begin to rise, resulting in a large uneven gap between the coffee powder particles inside the coffee handle after a certain degree of expansion. Hot water will instantly penetrate the coffee powder in such a gap, resulting in insufficient extraction in the later stage.

Therefore, under such analysis, you will realize that the flow rate and state of espresso are not determined entirely by the force of pressing powder. A series of reactions inside the handle show that in order to make the flow rate and extraction stable, it is necessary to ensure that the space for coffee powder expansion is reduced, and the gap after expansion is uniform, so that water can steadily and evenly pass through coffee powder to achieve uniform extraction and control the extraction time. Since the origin of the name espressso is related to pressure, I think it should refer to the water pressure of the coffee machine and the whole extraction pressure inside the handle of the coffee machine, so it is necessary to comprehensively consider the water and coffee powder and expansion space inside the handle, not just consider the pressure on the surface of coffee powder, understand this change and principle, you can adjust your grinding degree and powder pressure and extraction time.