The expression of the grindability of hand-brewed coffee, how to distinguish between coarse and fine sugar

From the beginning to the end, we do not have a clear description of the thickness of the degree of grinding. So when people talk about the degree of grinding, there will be a variety of different expressions, some people will use "fine sugar" to describe it, some people are used to using the scale size of the bean grinding equipment, and others use the sieving rate as in the front street. Although these methods have some limitations, their ultimate goal is the same, in order to better understand the size of coffee powder particles.

The scale reference method uses the scale value of the bean grinder to do the thickness parameters of the coffee powder. generally speaking, it takes the current popular and universal bean grinder as the description reference. For example, the 7 scale of EK-43, the 26 frame of C40 and so on.

It is a reference method with big drawbacks, and the dazzling variety of bean grinders on the market makes buyers less likely to hold the same model. The grinding values of different models are different, and the coffee powder ground by different bean grinders will be particles of different sizes at the same scale. When you have the same type of grinding equipment, because its installation, use and maintenance status are different, then, even if the same scale is still difficult to be used as a reference standard. If the two sides hold different bean grinders, it will be more difficult to apply this reference method. Visual analogy is that we use some common objects to compare the grinding thickness of coffee powder. Coarse sugar and fine sugar are the most commonly used adjectives of grinding degree.

This kind of description is the most direct reminder of the size of the degree of grinding, but it is also an "unreliable" description, because it is difficult for human eyes to distinguish between small objects. when our eyes are attracted to some focus objects, it's easy to ignore other details. Take a small example: if you use a hand bean grinder to grind a finer coffee powder, there will be more or less larger-looking particles, and these particles will easily attract your attention and make you mistakenly think that this "coarse sugar" is ground. But it is actually the grinding degree of "fine sugar" particles. The eyes mislead your judgment, which invisibly increases the probability of error. Therefore, in the preliminary judgment of the degree of grinding, we can spread out the coffee powder, observe the whole, and reduce the error rate to the lowest. The screen calibration method is the most common one in the front street articles, which is mainly used to calibrate the cup measurement and the grinding degree judgment of hand punch thickness. The front street uses a No. 20 standard screen with an aperture of 0.85mm. This screen is not used to screen fine powder, it is mainly used to judge the degree of grinding.

Its advantage is that the replication is strong, as long as the screening rate is found, different bean grinders can also find the same grinding degree. The disadvantage is that it is a bit of a waste. The way to use it is to take 10g coffee beans (or a multiple of 10, which is convenient for calculation, the more the powder is, the more accurate the data is), choose a grinding degree to grind, then pour the ground coffee powder into the sieve, and then shake it! Shake it horizontally, left and right! Shake until the particles no longer fall significantly (usually 3mi for 5 minutes). The falling particles are then weighed and the screening rate can be obtained by dividing the weight of the powder by the total amount of powder.

To a chestnut: we use 10g powder, through the amount of powder is 8g, then the over-screening rate is 80%, if we want to reach 90%, we can improve its over-screening rate by fine grinding. No matter what the reference method, the parameters given are ultimately to reduce the trial and error of new contact with beans. For example, the size of coarse sugar or the over-screening rate of 80% of the screen can enable us to roughly adjust the grinding to a suitable range before brewing, combined with the speed of water and the time of extraction when we brew. Eventually, we can consume less coffee beans to adjust the grinding parameters that are most suitable for it.

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Front Street Cafe

No. 10 Baoqian street, Yandun road, Dongshankou, Yuexiu district, Guangzhou, Guangdong province