Hand-brewed coffee and water injection technique! Tips and methods for injecting water into drip coffee! How to add water to coffee?

Qianjie stores often welcome some friends who teach themselves to make coffee by hand at home to discuss issues related to brewing with Qianjie. Many friends said that although the parameters they use are exactly the same as Qianjie recommends at the store, the coffee brewed tastes always good and bad, and I don't know where the problem is.

There are no exceptions to this situation. The main reason is that the water flow when making coffee is not stable enough, so the coffee is sometimes good and sometimes bad.

That's right! Just like the various parameters we need to pay attention to when making good coffee, the water injection during brewing is also very particular. The location, path, height and size of the water flow will have a direct impact on the extraction of coffee. According to SCA experimental data, the higher the stability of the water flow, the higher the uniformity during extraction. So if we want to make a cup of delicious coffee stably, in addition to controlling various extraction parameters, we also need to control the water flow during brewing! So today, Qianjie will come to share with you how the water current affects the extraction of coffee, and how we should match the water current when brewing to stably make a cup of delicious coffee.

Key point 1: Water injection position When a novice first comes into contact with hand-brewed coffee, we can first focus on the water injection position, that is, the landing point of the water flow.

The location of the water flow determines the amount of coffee powder and the amount of hot water can contact. Taking a conical filter cup such as V60 as an example, the powder layer structure of the conical filter cup belongs to an inverted cone, so the thickness of the powder bed becomes thicker as it goes to the center, and thinner as it goes to the periphery. Naturally, hot water injected in different locations will come into contact with different coffee powders and quantities, and the amount of substances dissolved will also change as a result. If we want to obtain a relatively uniform and efficient extraction of coffee, we first need to ensure that the hot water can come into contact with the most coffee powder or the entire time before dripping out of the filter cup, rather than slipping out of the filter cup. The channels supported by the ribs slip away and form bypass water. To do this, we only need to control the scope of water injection.

Taking V60 as an example, if the impact force of our water flow is not very large, we only need to control the range of water injection to two-thirds of the size of the powder bed. Within this range, there is almost no chance of hot water breaking through the powder bed to form bypass water due to its high impact, and coffee will be more fully extracted. (Qianjie here is just an example. During actual brewing, various factors still need to be combined to determine the location of water injection)

Point 2: Water injection path. After we understand the scope of water injection, the next thing to do is to make the coffee powder move in the filter cup! The reason is very simple, because we want to improve extraction efficiency!

Qianjie has often shared the principle of coffee extraction recently, so everyone must be quite familiar with it. To put it simply, when hot water comes into contact with coffee powder, soluble substances in the coffee powder will transfer to water with relatively low concentration due to the difference in concentration gradient. As there are more and more flavor substances in the water, the concentration becomes higher and higher. When the internal and external concentrations become more and more balanced, the extraction efficiency becomes lower and lower, that is, the dissolution rate of flavor substances will decrease. Drip-filter hand-flushing is not like brewed coffee, which does not have sufficient contact time between water and coffee powder. If we just pour water at a fixed point like this, we will eventually get a cup of coffee that is not strong enough and has a very thin taste. Because the extraction is not sufficient, there are not enough flavor substances to support the taste and taste of the coffee.

If you don't want to drink coffee that is not sufficiently extracted, then we need to control the water injection kettle to circle it so that the water can stir the coffee powder to form turbulence/turbulence, so that the extraction efficiency can be improved, and the taste and taste of the coffee will naturally be more plump. Just like the example of Banlangen particles often cited on Qianjie, if we just pour Banlangen particles into hot water and ignore it, then it will melt very slowly. But if you use chopsticks to stir it, it will melt away in just a few seconds. So if we want to speed up the dissolution of flavor substances, we can let the water flow stir the coffee powder like chopsticks, allowing the coffee powder and water to move relative to each other, which can greatly increase the dissolution rate of flavor substances.

But it should be noted that Qianjie is not saying that fixed-point water injection is not good. The difference between fixed point water injection and loop water injection lies in the difference in extraction efficiency. They have their own suitable use scenarios. We need to use different water injection methods according to different situations, so there is no good or bad.

Key point 3: In addition to the winding, there are two other factors in the water injection height that will affect the extraction efficiency. The first one is the water injection height, that is, the distance between the water injection position and the liquid surface. The water injection height determines the impact force of the water flow. The higher the water injection height, the stronger the impact force of the water flow will usually be. The stronger the impact force can set off a stronger turbulence, then naturally, the higher the extraction efficiency will be; on the other hand, if the height of water injection is lower, the impact force of the water flow will be smaller, and the smaller the turbulence will be generated, and the extraction efficiency will be lower.

In the same way as the choice of winding and fixing points, the height at which water should be poured during the brewing process depends on our needs. If you want to improve extraction efficiency, you can appropriately raise the height of water injection, and vice versa. But what everyone needs to know is that in addition to extraction efficiency, the height of water injection will have three different effects! Movement of coffee powder: Qianjie mentioned earlier that when the water injection position is higher, the turbulence will usually be greater. The turbulence will change the position of the coffee powder. If the agitation is too large, it will easily cause some fine powder that quickly absorbs water to sink to the bottom of the filter cup and block the filter paper, slowing down the water flow and prolonging the extraction time., coffee will have a chance of being over-extracted.

Changes in water temperature: The second is the impact on temperature! In the tweet "How Much Water Is Best to Make Coffee", Qian Jie shared that the water temperature we usually mention for extraction is not the water temperature that is actually extracted. The actual water temperature of extraction will be absorbed by various factors during the extraction process and will decrease. For example, the water temperature in the pot is 92°C, and the actual water temperature for extraction is only 80°C+. Various factors include the height of water injection. The higher the height, the more air the hot water will come into contact with, and the more heat it will naturally be sucked away, and vice versa. The famous pine house brewing is to reduce the water temperature during brewing by increasing the height of water injection, so that coffee can be properly extracted.

Pattern of water flow: I believe careful friends have discovered that there is no certainty in front of Qianjie that the higher the water injection height, the stronger the impact of the water flow will be. This is because when the water injection height reaches a certain level, the water flow will not be able to maintain the attitude of the water column and will break into drops of water. Water droplets cannot stir the coffee powder, so its extraction efficiency is much lower than that of the water column. If we don't want the above three negative effects to occur during brewing, then we need to control the height of water injection. As usual, Qianjie recommends that you control the height to a distance of about a fist from the liquid surface.

Point 4: The size of the water flow is ultimately the influence of the water flow. The size of the water flow refers to the speed/rate of water injection, that is, how much hot water you can pour out in one second. The more hot water you pour out, the relatively larger the water column/current, and vice versa. The speed/size of the water flow has three different effects! In addition to the impact force of the water flow mentioned by Qianjie, there are also extraction time and the distribution of coffee powder!

Effect of water flow size on time: The water flow size will affect the extraction time. The larger the water flow we use when brewing, the faster the water flow will be, and vice versa. How the size of the water flow affects the powder bed: When the amount of water injected is greater than the amount of water injected, the liquid level will be raised, so when we want to raise the powder bed, we only need to increase the injected water flow to raise the water level and at the same time Let the powder bed be raised. The specific operation and the role of raising the powder bed need to be understood in the article "Portal", which will not be described in the front street here.

How to inject water when making coffee by hand? To sum up, we can know that the location, path, height and size of the water flow will have a direct impact on the extraction of coffee. If you want to steadily brew delicious coffee, try not to let the water injection change too much during the brewing process. For example, the water flow fluctuates between large and small, and the height varies between high and low, which will reduce the uniformity of coffee extraction, and the coffee will become less delicious.

If you don't know how to fill water, then you can refer to the daily cooking methods used in Qianjie. We can share them in detail in the article "Three-stage Cooking is That Simple". Interested friends can move forward and understand it for themselves ~

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