The influence of Water injection height of hand-brewed Coffee on Coffee Flavor introduction to the standard action of brewing coffee

Friends usually in the coffee when there is no attention to their own injection of water column height from the coffee level how high. What does the height of this water column mean for us to make coffee?

According to the observation of Qianjie Street, most friends in the coffee when the height of the water column is about 0-7cm, some like to put the spout close to the liquid surface water injection, some like to pull out a long straight water column water injection. Of course, there is no right or wrong way to brew coffee. Front Street is just to discuss how the height of the water column will affect coffee extraction, so that everyone can find the right way to brew coffee. - Water column penetration in hand brewed coffee, water column "wash stir" coffee powder is a way to speed up the release of substances from coffee powder. The water column we usually inject is actually not a cylinder, but an inverted cone with a thick upper part and a thin lower part. Therefore, when it reaches a certain height, the water column will become a continuous droplet or even a break. In the general brewing situation, we will avoid the phenomenon of interruption, so the maximum height of water injection is relatively restrained, generally 7 cm is already the limit (except for specific brewing methods).

The higher the height of the water column, the stronger the penetration, and the stronger the washing of the coffee powder layer. Relatively low water column height, penetration is more gentle, tumbling coffee powder layer effect is not so obvious. "What should be noted here is that it is not that the stronger the tumbling coffee powder layer, the better. Many times, the bitter taste of coffee is caused by excessive stirring of the tumbling powder layer."- An experiment was done in Qianjie, using exactly the same brewing parameters, only changing the height of water injection for comparison, which was 2 cm and 10cm respectively. The result was a coffee concentration of 1.44% at 2 cm, much higher than 1.30% at 10cm. The difference in concentration is caused by the loss of temperature. The temperature mentioned in the coffee parameter shared by Qianjie is the temperature of the water in the hand brewing pot. In fact, when the water flows out of the pot, the temperature will definitely decrease. This is because water column loses its temperature when exposed to air. When the water is injected at a high level, the surface area of the water column exposed to the air is larger, and the more temperature is lost, the lower the temperature of the coffee actually extracted in the filter cup, and the lower the natural concentration.

Therefore, Qianjie does not recommend the use of large filter cups for small amounts of powder is also the reason. Due to the height of the filter cup, it is relatively high when injecting water, the temperature loss is large, and the difficulty of injecting water is greatly increased (it is easy to touch the filter cup side). The vertical problem of water column Most hand-washed pot spouts are not vertical when they come out of the water. They are parabolas that float outward a little, and gradually tend to be vertical with height. Therefore, the method of water injection close to the coffee surface has a high probability of uneven extraction due to the arc produced during water injection. The specific powder layer performance is that the powder wall on one side near the injection kettle is thicker, and the powder wall on the other side is thinner, and even may break through the powder wall.

Therefore, when filling water, it is best to be at least 2-3 cm away from the liquid surface, so that the water column with curvature just out of the spout straightens.

Basically, the water injection height affects only stirring force, extraction temperature and water column vertical. The height of the water injection can be any number, but it must be clear how the coffee will change at such a high level of water injection. For example, Qianjie does not recommend that everyone stick to the liquid surface to brew, because it is easy to extract uneven, but there are also people who stick to the liquid surface can also extract evenly, but also very good to drink. The height of the water column in the front street is usually kept at 3-4cm when brewing coffee, not because this height is the best for brewing coffee, but because the probability of accidents is the smallest at this height, which is easier to use.