Learn what a coffee ground bed is and how to judge extraction from a coffee ground bed

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Coffee powder bed height-whether the powder bed is stacked or not, how does it affect the coffee extraction flavor?

Too high → in powder bed can easily lead to laminar flow, and there is a risk of over-extraction and insufficient extraction.

Too low → in the powder bed can easily lead to the rapid flow of water through the coffee powder, resulting in the phenomenon of insufficient extraction.

[recommended powder bed height 2.5-5 cm, highly respected by SCAA Professor of American Fine Coffee Association]

Due to the accumulation of → on the high wall of the filter cup, some coffee powder could not be extracted completely, and the integrity of the flavor was poor.

When making coffee by hand, the moderate height of the powder bed can have a good disturbance phenomenon, which is very important for the extraction of coffee. The disturbance can make the coffee powder absorb water evenly and show a saturated state.

Of course, the control of spoiler is not only the height of the powder bed, but also the appropriate water entry rate, the grinding fineness, the material, size and shape of the filter cup.

I personally prefer all the powder to participate in the extraction of shallow and medium-baked beans, (uniform extraction = immersion in water at the same time), so the ideal state of uniform extraction is horizontal without hanging wall.

For those who are moderately baked and moderately deep, I will choose the shape in which the powder hangs on the wall, that is, it looks like a small pit or a slight couch in the middle. At the beginning, it does not destroy the powder layer with a steady and supple flow, reduces convection and is fully extracted. The second half of the process is uniform water injection, the process will also lose temperature seriously because of a long time or stages, in order to prevent excessive extraction in the middle, far from the target value will also deliberately lower the water temperature, play a dilution role. The taste will be more mellow.

Affecting the extraction conditions, more powder, fine grinding, high water temperature and fine water flow are all to enhance the flavor of the first half of the extraction. What about the second half? Of course, the proportion will be very small, and sometimes it will feel empty in the second half of the drink, and the sense of balance of the whole cup of coffee will disappear.

Why is light roasted coffee so sour? Some people say that it is because the shallow baking retains the fruit acid and more ingredients, which makes it so sour. Isn't it supposed to be sour, sweet, smooth and balanced? Then. What about sweetness and grease? Because the powder is too fine, the water temperature is high and the water flow is slow. If you try to reduce the extraction concentration of the first half, you will get the flavor of the second half. But if the health is too low, you will only get a cup of sweet water.

Finally, I think that on the issue of paying too much attention to the so-called "pink wall shape", we should not ignore the taste of real experience. A good cup of coffee is all the key to extraction.