Principle of dripping method in Coffee extraction-cleaning of Delong Coffee extractor

Principle of dripping method in Coffee extraction-cleaning of Delong Coffee extractor

Now you should understand the relationship between perfect extraction, underextraction and overextraction. But the whole process of extraction is much more complicated by adding the factors that previously affected the extraction.

In fact, some of these factors need to be paid attention to and summarized, while others need to be controlled as much as possible.

Why do you say that?

For example, the thickness of the powder, you can refer to the scale of the bean grinder, the particle size is also more intuitive visually, experienced friends even if changed to the bean mill also have a direct concept of the powder thickness. The amount of powder can be controlled by weighing, the level of water temperature can be controlled by temperature, extraction time and the ratio of water to powder, these are easy to control to be more accurate, so these factors are stable through continuous attempts and records.

There are two parts that are difficult to control and try to control. It is difficult to make two identical cups of coffee, which is also caused by these two factors.

One is the quality of grinding, which depends on the performance of the bean grinder. Today's technology still cannot grind coffee beans into a completely consistent coffee powder, and the difference in particle size will affect the stability of the extraction process.

The second is the convection of water, which goes back to the example of perfect extraction of two drops of water: a cup of coffee needs to extract not a coffee powder, but a pile, even if the particles are exactly the same size. we can't exchange each with two drops of water, which leads to the next factor.

The strength of convection

When we apply convection to hand flushing, there are many schools on the market: segmented water injection, one-time water injection, fast flushing, slow flushing, turning from the inside to the outside, flushing only in the center, there is also a very slow extraction of a little coffee and then diluted, and so on. The coffee produced by each genre has its own style, and the producers are often confident or even convinced of their own genre, but you may find that no matter which genre, you can make several kinds of coffee, some of which are not good at all.

To put it bluntly, the punching methods of these different schools mainly adjust the strength of convection, such as the strong convection of fast rush and the fierce exchange of water and coffee powder, which makes it easier to highlight the flavor and over-extract. The slow rush will be softer, but the flavor will be weaker.

Barista, who understands the conversion of the extraction rate, may have seen the problem-such adjustments and conclusions are completely meaningless! Because in the case of no concentration meter, we can not get the tds reading, nor can we calculate the extraction rate! Excessive extraction and insufficient extraction can only be said to be subjective and completely unconvincing.

Let's help the barista together, or 18g coffee. When the grinding scale is changed, the relationship between the two variables we will get is

1. Ebf 50%, the extraction time is prolonged.

2. The extraction time remained unchanged for 28 seconds, and the ebf value increased.

In pass extraction, the change of ebf will also correspond to the change of extraction rate. Therefore, when we decide to modify the extraction rate by adjusting grinding, ebf can not be changed. Otherwise, the extraction result will become uncontrollable. After understanding this truth, my mother no longer has to worry about the extraction time of the boss. Grind it with fine grinding and continue with 18g in,36g out. Combined with the previous extraction results, I finally found the performance I wanted in the cup.