What does hand-brewed coffee stop mean? What is the purpose of dripping coffee interception? What is the difference between coffee powder-to-water ratio and powder-to-liquid ratio?

In the process of brewing coffee, when there is still a certain amount of liquid left in the filter cup, it is removed when it is not fully permeated, a behavior we call "interception".

Then, because the closure will remove the coffee liquid at the end, and many friends think that the bitter taste of the coffee comes from the coffee liquid at the end, the act of river closure has become a necessary operation for most friends when brewing. But what Qianjie wants to say is that river closure also needs to be used according to the situation and the way of cooking. The use of river closure in inappropriate circumstances will not only not make the coffee taste better, but will also be prone to putting the cart before the horse.

Why can't river interception be used at will? First of all, we need to know that bitterness is not just dissolved in the end. Qianjie often mentioned that the dissolution of bitter substances runs through the whole process. Just because it is a macromolecular substance, the dissolution rate will be relatively slow, and when the sweet and sour substance is dissolved, it will continue to dissolve because of its insoluble properties. If we continue to extract after the sweet and sour substances are dissolved, then this will cause the substances dissolved in the coffee to be negative.

But under normal circumstances, we will work out the brewing framework before brewing, so that the extraction ends when the sweet and sour taste dissolves, so that the release of negative substances can be avoided and the coffee can have excellent performance. But Qianjie alone may not be so easy to understand, so you can actually try it. Under the condition that the brewing frame is reasonable, we can try to take out the coffee liquid at the end of the brewing process and drink it. Then we will find that the final dissolved coffee liquid can hardly feel the bitter taste, only the sweet and sour taste is light, slightly tea, and there is no imagination of bitterness and miscellaneous. The reason is very simple, because the parameters are reasonable, so even the end of the coffee liquid, will not extract the negative substances of coffee, and its main function is to dilute the overall concentration of coffee.

If there is an obvious bitterness at the end of your paragraph, then our focus should be more on the parameters. It is due to the use of unreasonable parameters that the negative substance is dissolved in the tail section. Otherwise, under normal circumstances (excluding unexpected situations such as blockages), unless the quality of coffee beans is not high, it will be very difficult for us to extract the negative taste under reasonable parameters. The shallow baked bean cooking frame commonly used in the former street is as follows: 15g powder, fine granulated sugar grinding, powder-water ratio at 1:15, water temperature at 92 °C, extraction time for two minutes. If we remove the end of the coffee before the drip is finished, then the cup of coffee may show these negative manifestations: too high concentration, incomplete flavor, lack of finish.

Because the coffee liquid at this end is included in our framework, when we intercept it, the concentration of coffee will be increased because there is not enough water to dilute it, so it is not so good to enter. At the same time, the coffee liquid at the end of this section also contains certain flavor substances, and when it is missing, it is equivalent to the loss of a certain flavor performance, including the tail rhyme made of bitter substances. Therefore, we can know that river closure can not be applied casually.

Under what circumstances can river interception be used? The use of river closure is mainly divided into two cases. the first is that we actively take the river closure as part of the cooking process and add it to it when we develop the extraction framework. For example, when using the ratio of powder to liquid as a unit of measurement. In fact, the operation of river closure is not a new operation that has sprung up in recent years. As early as the end of the last century, river closure has been widely used in coffee circles. But at that time, the application of river closure was a helpless move. Because at that time, there was no convenient measuring tool as it is now, and both the water temperature and the liquid weight had to be speculated according to experience or the capacity of the cup.

So at that time, most people used the ratio of powder to liquid when making coffee. The so-called powder-to-liquid ratio refers to the ratio of coffee powder to coffee liquid filtered out. Since it is impossible to measure the amount of water injected, the liquid weight can be calculated by observing the water level of the coffee liquid in the cup and the capacity of the cup. When the coffee liquid reaches the target water level, the filter needs to be removed to prevent the remaining liquid from seeping out of the filter. Because the amount of coffee liquid oozing back is already outside the target, beyond the extraction range, there is a high probability that there will be negative substances. Therefore, it is necessary to cut it off by intercepting the river at this time to avoid the obvious negative performance of coffee.

Another situation is passive choice, which I believe you are very familiar with. When the coffee beans are too shallow, too hard, or too much fine powder, clogging can easily occur in the process of brewing.

The emergence of blockage will force the extraction time of coffee to be prolonged. If corresponding measures are not taken immediately, coffee will easily lead to over-extraction due to too long extraction time, and some negative flavors such as bitterness and astringency will be dissolved. Therefore, in this case, we will be forced to use closure to reduce the addition of bitter substances, and then based on the concentration of coffee to determine whether the need to pour into the bypass water for dilution.

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