Basic knowledge of making coffee by hand! What is the timing of water injection for three-stage brewing? The right way to brew coffee!

Although the water injection operation of hand-brewed coffee looks very simple, in fact, it always contains a lot of small details that can influence the taste. As a result, people often pay attention and explore from some strange perspectives. For example, a point that people have paid more attention to recently is: when extracting coffee by segmented water injection, do you need to wait until the flow is over before injecting water?

Before answering the question, in case it is difficult for some rookie friends to understand, let's first answer what is segmented water injection ~ the so-called segmented water injection means to divide the total water injection into multiple / multi-stage injection. Because steaming is to better allow subsequent hot water to extract the substance from the coffee, it has become an inevitable and important part of most brewing methods (depending on the situation, of course). When we use staged cooking, there will be a waiting time before each stage of water injection, because we need to let the water injected into the filter cup seep out first.

This has three main purposes: the first is to make hot water better extract the coffee powder at the bottom; the other is to prevent the filter cup from overflowing due to insufficient capacity; and finally, to prolong the extraction time. So back to the point, should we wait for the water to dry before injecting the next section of hot water? Or should it be injected into the next section before the water level is dry, as introduced by the major bloggers?

Should segmented water injection wait for the flow to dry before injecting the next section of hot water? The answer to this question is actually very simple. We only need to know the difference between the two to know where the best time to inject water is. In fact, Qianjie has done relevant experiments before, and interested friends can refer to the previous articles. In the interval stage, if the injection is carried out until the water is completely finished, it will bring a certain extension to the total extraction time on the original basis. The extended time will change according to the situation of the beans! The higher the density and hardness of the bean, the longer it takes for it to dry out.

As we all know, time is also a link that determines the efficiency of extraction. The longer the extraction time, the higher the extraction efficiency, and vice versa. So we can know that this waiting can change the extraction rate of a cup of coffee. Qianjie used three-stage cooking in the last three groups of experiments, that is, the water injection after steaming was divided into two stages, with a waiting time in the middle. The result is: for anaerobic coffee, there is almost no effect, because they enter the water faster, so it does not take too long to wait for the water to dry, 10 seconds is enough. And the main impact is the conventional treatment, the degree of baking is shallow and deeper (more fine powder) beans! Because of the high density and hard texture of light-roasted coffee beans, more fine grinding is needed for the flavor substances in the body to be fully extracted. Fine grinding will reduce the gap between powder and powder, and the penetration rate of water will be slower, so it will take longer to seep out the coffee liquid at the end of the second stage of water injection, greatly prolonging the extraction time!

On the other hand, deep-roasted coffee is relatively brittle, so although its grinding degree is thicker, it breeds more fine powder (poor quality of the bean grinder will also lead to the growth of a large number of fine powder). At the same time, it is easier to be over-extracted because of its loose structure and easy extraction. Therefore, the two of them adopt the method of injecting water after waiting for the water to dry, so it is easier to extract because the extraction time is prolonged. So you can know why Qianjie's cooking description in the article is always "waiting for the bottom of the water level before injecting the next section of hot water." Because waiting for the water to dry does not apply to all coffee beans! The extraction time will be prolonged, the extraction temperature will also change, and the fault tolerance rate is low.

But Qianjie does not say that the method of "wait for the coffee liquid to dry and then inject water" cannot be used, but it needs to reformulate the extraction parameters to improve the fault tolerance rate of extraction. After all, the reason for overextraction is that the extraction efficiency of the parameters matched with it is too high and not suitable enough! That's all.

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