Does hand coffee also have a channel effect? What is the reason for the slow accumulation of hand-brewed coffee?

Thanks to the development of the Internet, there are a lot of teaching videos of making coffee on the Internet. Therefore, there are many friends who learn to make coffee by watching videos. Some friends are even serious enough to split the video into frames, accurate to the number of seconds at the beginning and end of each segment of water injection, and the action of water injection.

When I began to practice, I found that although I could accurately control the time of starting and ending water injection, the next launching speed was not consistent with that in the video. The water in the filter cup was silting up, and the launching speed was very slow. Naturally, the whole brewing time is longer than that in the video. As for why this phenomenon occurs, Qianjie believes that it is mainly due to these typical reasons.

The first point is that I didn't find the right video. For beginners who are new to coffee, they have not summed up the logic of brewing methods and do not know enough about coffee beans. You know, coffee beans with different roasting degrees and hardness are different in the performance of the powder layer during cooking. For example, shallow roasted coffee has a large particle density and is easy to sink at the bottom when brewing, so it is more likely to have stagnant water than deep-roasted coffee. For example, coffee beans that are almost out of gas (not very fresh) are also more prone to stagnant water when brewing. Therefore, if the coffee beans you make are not the same as those shown in the video, then the powder bed must not be the same. Therefore, Qianjie especially does not recommend some friends to ponder in front of a video. If you are really self-taught by watching the video, you can first look at what kind of coffee beans you are making, and then search for the cooking video of this coffee bean. Remember to watch several different videos, find out what they have in common, and never copy them in a second. The second point is the most common problem of grinding degree and fine powder. The speed of launching is related to the thickness of coffee powder, if the coffee powder is too fine, it will hinder the decline of water. Generally used for hand-brewing coffee powder grinding degree is about the size of coarse sugar, if you use the No. 20 screen to screen, coffee powder pass rate between 70-80% of the thickness.

But we all know that coffee powder can not be absolutely uniform, it will certainly be mixed with thicker particles and finer particles. The phenomenon of stagnant water usually occurs when brewing coffee because the grinding quality of the bean grinder is too poor and produces too much fine powder, which will block the drain hole when brewing, causing the water to flow down (the water is very slow).

The third point is the mode of water injection. You can first take a look at the difference between the following two water injection methods.

The first method is to push the powder into the water. You can see that the water injection after steaming starts in a small circle from the center. The coffee foam emerges, making the original coffee burger bloom, and the coffee powder is pushed to the edge to form a powder wall. In this way, the powder bed will be thinner and the water will be more smooth.

The second is conventional circular water injection, compared with the first, only the first stage of water injection after steaming is different, this section of water injection is first around a larger circle, flushing out the foam, but also thinning the powder wall, the powder bed is thicker. So the overall launching speed will be more than 20 seconds slower than the first method. If you usually feel that coffee is slow to enter the water, you might as well try pushing the powder.