What is the function of the powder sieve? Screen out the effect of fine powder on coffee extraction?

Professional coffee knowledge exchange more coffee bean information please follow the coffee workshop (Wechat official account cafe_style)

Ground coffee is to increase the speed of coffee extraction, different extraction methods need to be matched with suitable grinding fineness, the finer the grinding degree, the faster the brewing time, such as Espresso uses extremely fine grinding, extraction time is between 20-30 seconds to extract espresso, but generally filter paper hand washing time is about 2 to 2 and a half minutes, Kono hand washing method is as long as 6 minutes, so it is necessary to use medium to medium rough grinding If there is a fine powder in the hand-made coffee powder, it is like using an Espresso machine to extract finely ground coffee for up to two and a half minutes, which will increase the bitterness and miscellaneous taste.

Moderate grinding is the most suitable grinding degree for hand-brewed coffee, but whether it is in the process of crushing coffee beans by hand bean grinder or in the process of chopping coffee beans by electric bean grinder, fine coffee powder will be produced, and the amount of coffee powder will change the flavor of coffee. In the brewing process, coffee fine powder will extract coffee contents such as caffeine faster than other coffee particles. So the substances that cause bitterness and miscellaneous tastes will be dissolved more quickly.

The following is to describe the degree of grinding in terms of the fineness of sugar or flour

Rough grinding is slightly thicker than second granulated sugar.

Medium grinding degree such as white granulated sugar

Medium fine grinding between fine sugar and white sugar

Fine grinding sugar

Very fine grinding like flour

The coffee powder sieve produced by Akira is called manual coffee brewing artifact, it has three functions: sieve, smell cup, and powder receiver. The sieve is metal iron mesh, and the mesh is very fine, so it will only sift out very fine coffee powder. Some coffee shops will use this sieve to remove coffee powder even if they use the general grade electric bean grinder.

The lower part of the sieve powder cup is wider, and the cup mouth is narrowed, which can retain the aroma. The sieve iron mesh can just pass through the cup mouth. When the sieve powder mesh is taken out after use, the fine powder can be left in the cup.

Put the sieve metal mesh into the cup when in use

Ye Jia Xuefei coffee beans

Country: Ethiopia

Producing area: Yega Xuefei

Manor: Kokona

Treatment method: washing

Extraction condition

Bean weight: 17g

Degree of grinding: moderate grinding

Water temperature: 90 degrees

Water injection: 226g (17g/7.5%=226g, 7.5g coffee powder per 100cc)

After pouring in the coffee powder, put the lid on the cup lid of the sieve powder cup and gently shake the sieve powder to screen out the fine powder which is smaller than the metal mesh of the sieve powder. According to the actual test results of the sieve, after shaking 18g coffee for 20 times, about 1g of fine powder, or about 5.6%, can be screened out. If you use a tea filter with a thicker mesh, it will screen out more than 2g, because the tea filter will sift out more than 2g except fine powder. Some of the medium-fine ground coffee powder will also be screened out, resulting in a waste of coffee powder.

The picture above shows that the coffee powder as fine as flour is much finer than the coffee powder with medium grinding degree.

Because the coffee powder using the sieve removes the fine powder, it will not be affected by the fine powder blocking the filter paper in the brewing process, and the speed of water passing through the coffee powder layer is accelerated, so the powder layer is less likely to expand, so the powder layer is flat after hand punching.

After removing the fine powder, the hand-brewed coffee without the bitter taste and miscellaneous taste caused by the fine powder, the overall coffee is much cleaner and brighter, the acidity of the fruit is also improved, and the smooth taste is also obvious. When you enter the taste, you can immediately feel the sweet and sour citrus flavor of Yejiaxuefei itself. after comparing the two, you unwittingly finish the clean cup with high brightness. The cup without removing the fine powder was left in the pot.

However, after the fine coffee powder is removed, the sense of layering of the coffee is also reduced a lot, so it can be shaken less, and there is no need to remove the fine powder too cleanly, and some layers can be retained. In addition, the degree of grinding can be slightly finer, using medium fineness to increase the sweet and bitter taste. After all, good coffee should have both sour, sweet, bitter and salty taste.