Why is the taste of the brewed coffee so weak? What is bypass water? How to make coffee by hand?

Bypass water refers to the water that is not involved in the extraction and production of coffee and is directly added to the coffee liquid. Generally speaking, there are only two reasons for bypass water to appear in the production, active selection and passive addition. Active selection means that we specifically set up a coffee making scheme that includes the addition of bypass water, such as hot American production: first extract espresso and then dilute the coffee concentration with extra hot water; or hand-brewed coffee, first use a small amount of hot water to flush out a pot of high concentration coffee, and then use extra hot water to dilute the coffee concentration. These hot water that we take the initiative to add is the bypass water that we actively choose.

But for most novice friends, the emergence of bypass water is more passive. For example, in the process of brewing, due to improper operation, part of the hot water did not pass through the coffee powder layer, but directly put on the filter paper and dripped directly down the filter cup to the lower pot. So what effect will the bypass water in this situation have on our coffee?

In the case of too much water in the bypass, coffee will have a light taste and a thin taste, that is, watery and widowed. Because the passive bypass water is evolved from the hot water we used to extract coffee, when part of the hot water for extraction is missing, the extraction rate of coffee will be reduced, and the taste will be slightly inferior because of the lack of extraction rate. At the same time, because this part of the bypass water will flow into the pot through the filter cup, it will also dilute the originally extracted coffee concentration, thus reducing the taste performance of the coffee. So, how can we avoid the production of bypass water in the process of extraction?

First, avoid circling too much, which is the note that Qianjie often mentions in the article: avoid circling too much! Because when we brew coffee, we will inject hot water in a circle, so that the hot water can extract as much coffee powder as possible, and stir the coffee powder at the same time, so as to increase the extraction rate of coffee. But many friends are always "extreme" at the beginning, using hot water to wet every place where coffee powder exists, even the edge of a cup where only a small amount of coffee powder is attached. Or in a big circle because the range is too large, washed in the powder wall is very thin edge of the filter cup.

In both cases, a large amount of hot water goes straight through the powder wall and filter paper and falls directly along the filter cup to the bottom of the pot, minimizing contact with coffee powder, which is the "passively generated" bypass water mentioned in front of the street. Therefore, when brewing coffee, we can try to narrow the circle to avoid hot water having the opportunity to bypass the coffee powder and have an impact on the extraction and coffee.

Second, the water level does not pass the powder wall, another situation is caused by the water level is too high, not over the powder wall. In many cases, in order to make the extraction more uniform, we will raise the powder bed to allow hot water to extract the coffee powder at the bottom.

However, some beans with shallow baking and high density are too heavy to rise with the rise of the water level. to put it simply, they cannot afford to build powder walls. If we still insist on raising the water level in this case, or if we insist on filling up all the target water, then this will happen in the picture below.

It can be seen that the water level is one degree higher than the powder bed, and some areas are not covered by coffee powder. The emergence of a situation like this is particularly unfriendly for multi-bone filter cups, because hot water will directly avoid the coffee powder and flow out from the side. Since it is not involved in any extraction, this part of hot water naturally belongs to "bypass water" and will have a certain impact on coffee. There are many solutions, such as reducing the flow of water. Through the slow injection of small water flow, the coffee liquid can be oozed in time so as not to accumulate in the filter cup, so that there is no need to worry that the water level will be higher than the powder wall and there will be a "bypass" to go.

However, this method often tests the skill and patience of brewers, so Qianjie is more recommended to add water injection paragraphs to reduce the amount of hot water injected into each section. For example, the water-washed shallow baked beans in Sidamo are so dense that we can't raise the powder bed during the cooking process. If the conventional three-stage brewing is used, the water level will be higher than the coffee powder because there is too much water in the second stage, so that the hot water has a "bypass" to go. In a case like this, it is best to divide the total amount of water injection into four to five sections, because with the increase of water injection paragraphs, the amount of water injected into each section will be reduced. For example, if the original three-stage water distribution is 30,120,75, then when it is changed to five-stage water distribution, it is 30,50,50,45.

The reduction in the amount of water makes it impossible for the water level to rise at all, and all the injected hot water can pass through the coffee powder, playing its due extraction obligation. But at the same time, we also need to appropriately reduce the number and intensity of stirring, because the more water injection paragraphs are separated, the longer the extraction time will be. If we don't want to drink a cup of bitter coffee, then we'd better reduce the intensity of water injection properly.

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