Why should I steam hand-brewed coffee? Why is the hot water used for exhaust gas twice the amount of water that is used for powder? What determines the concentration of coffee liquor?

Today, Qianjie turned to an ancient topic, which is very interesting, so I would like to share it with you. That is: "will it be better to remove the steaming liquid from hand-brewed coffee?" The reason for the release of this problem is also very interesting, and listen to Qianjie explanation ~ as we all know, the purpose of steaming hand-brewed coffee is to moist and discharge the carbon dioxide that hinders the extraction of coffee powder. so that the subsequent injection of hot water can have an excellent extraction environment, better bring out the flavor substances in the coffee powder. This means that we need to set aside more hot water for the main extraction stage after steaming, so that they can maximize their value. Therefore, we have to limit the amount of hot water that can be used in the steaming process.

As it happens, dry coffee powder needs to be saturated by absorbing hot water. According to experimental statistics, coffee powder needs to absorb about twice its own weight. Therefore, the hot water used in steaming is set to twice the amount of powder. In this way, the powder can be steamed and saturated at the same time, and the hot water will not be "wasted" because of too much. However, these hot water will not be completely absorbed by coffee powder. Because of the uneven distribution of hot water, it can not be evenly distributed to each coffee powder; in addition, the size of the injected water and the thickness of the grinding particle size also directly determine the infiltration velocity of hot water, which indirectly affects the absorption of hot water by coffee powder. Therefore, after we pour in the hot water, not all the hot water will be absorbed, but some of it will seep into the pot.

Then some people speculated that since the role of this part of the hot water is to wet the coffee powder, it removes the obstacles of extraction. Doesn't that mean that their extraction environment will be weaker than the subsequent injection of hot water? So, will the concentration of the permeated coffee liquid be lower? If you remove it, will it prevent them from diluting the concentration of the whole cup of coffee?

Do you need to remove the coffee liquid oozing from steaming? I don't know if you have noticed that such a behavior is actually similar to river closure. The so-called closure is because the coffee liquid extracted from the tail may have a lot of miscellaneous smell, so we have to cut off the coffee liquid from the tail to avoid the obvious negative taste in the coffee. The reason for removing the coffee liquid during steaming is to avoid diluting the concentration of the whole cup of coffee. If the two are used together in the same pot, it is the so-called "pinch the head and go to the tail".

With regard to river closure, Qianjie has shared it in detail before. If you are interested, you can jump directly. "does hand coffee have to be intercepted?" ". It roughly means that river closure is feasible, but it should not be used indiscriminately. However, for "pinch", that is, to remove the coffee liquid during steaming infiltration (too long, hereinafter referred to as "steaming liquid"), Qianjie can make it clear that this is not feasible! Why? Qianjie to make a pot of coffee to explain to you ~ the beans used in Qianjie this time are Panamanian green label Rose Summer, because the medium-shallow roasted beans absorb water at a moderate speed, and a certain amount of coffee liquid is bound to seep out when steaming. And because of its outstanding flavor, it can help us to compare the difference between steaming liquid and non-steaming liquid more directly. The extraction parameters are as follows: 15g coffee powder; 1:15 ratio of powder to water; grinding degree: 10 degrees of Ek43, fine granulated sugar grinding, pass rate of No. 20 standard sieve 80%; water temperature 92 ℃; filter cup V60; cooking method is still three-stage. So let's start our steaming, using twice the amount of water (30ml) of powder for 30 seconds! Qianjie finished injecting 30ml hot water in 8 seconds, and then in 10 seconds, the coffee liquid began to ooze!

After 24 seconds, the coffee liquid no longer seeps out, and we pour the coffee liquid from the pot into a small cup and set aside.

Then press the zero button on the weight to restart our extraction (this is easier to calculate)! In the second stage, 130ml hot water is injected in a large circle with a small flow, and then the remaining 65ml hot water is injected in a small circle when the water level is about to hit bottom. After the extraction, we can begin our comparison!

In fact, we can see the answer to this question directly from the picture below, because the steamed coffee liquid is very dark, which means that it has a high concentration. But in order to better verify, the process that should be taken is absolutely indispensable.

Through the test of the coffee concentration meter, we can get that the concentration of this pot of coffee without steaming liquid is 1.25%. On the other hand, it has a hint of jasmine in its flavor, high sweetness of melon, a little acidity of berries and a long finish.

Then we add the steaming liquid (15ml) to the pot of coffee and stir well.

The concentration was then re-measured to 1.38%. In terms of flavor, the reintegrated green rose summer has brighter citrus acidity, higher overall sweetness, more prominent flavor and fuller taste.

To sum up, we can conclude that the coffee liquid permeated during steaming is also very important! The flavor substances in coffee are limited and will gradually decrease with the advance of extraction. Although the extraction environment of the hot water during steaming is not so excellent compared with the hot water injected in the formal extraction process, the flavor substance of coffee powder is the most abundant and fullest at this time. So at the beginning, even without a good extraction environment, hot water can extract a large number of flavor substances, so this little coffee liquid has a very high concentration (high content per unit flavor substance). If we give up this extremely high concentration of coffee liquid, we will not only lose the rich flavor experience, but also reduce the mellow thickness of the taste. So, don't try this kind of thing of losing both husband and soldier.

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