What's so fastidious about brewing coffee and steaming water? Correct steaming quantity and time parameters of hand-brewed coffee

Wet the coffee powder with a small amount of water and wait for the coffee powder layer to expand and exhaust, a process we call "steaming". Basically, steaming steps will be carried out in the process of making coffee. So what effect does this steaming have on making coffee, and what effect does it have on the flavor of coffee?

When we make coffee, we steam first, mainly in order to discharge the carbon dioxide that hinders the release of flavor substances from the coffee body, so that we are more likely to flush out the flavor of the coffee. Therefore, hand flushing is added to steaming to make it easier for us to make coffee.

Can I make coffee by hand without steaming? In fact, steaming is not necessarily a necessary step for hand-brewed coffee. For example, the "one-throw" method shared in front of the street is to grind the coffee powder to a very fine state, using an one-time injection of water into the coffee powder, skipping the steaming step. But for most brewing methods, the addition of steaming steps can make it easier for coffee to improve extraction stability and extraction rate. After steaming, the coffee powder layer will emit carbon dioxide, which will not affect the subsequent water injection. If the steam is not steamed directly or steamed insufficiently, the powder layer will constantly appear bubbles to hinder the extraction during the cooking process. Since steaming is so important for hand flushing, is there anything to pay attention to during steaming, or what is the impact of changes in water injection volume, steaming time and water injection methods on the flavor of coffee? The amount and time of steaming is mainly determined by the state of the coffee powder layer, and the ideal state is that the amount of water just wets the coffee powder completely, and the amount of water dripping into the pot is relatively small. The judgment of the steaming time is to observe the expansion of the coffee powder layer. When the coffee powder expands, it means that the gas in the coffee powder is being discharged, while the coffee powder layer tends to be stable and no longer "exhale", indicating the end of steaming exhaust.

And the general practice, will use 2 times the amount of coffee powder for steaming, the steaming time is about 30 seconds. So what effect will it have on the flavor if the amount of water is different from the time? Let's take 2 times the amount of coffee powder as the standard steaming water and 30 seconds as the standard steaming time. So:-when the amount of water injected is less than the standard amount of water, it may cause the coffee powder layer not to be completely wet, and if the water injection technology fails, the coffee powder at the edge of the surface may not be wetted; it may also appear that the surface looks like all the coffee is wet, but part of the coffee powder at the bottom will not be completely wet. The coffee brewed in that way may have an astringent feeling.

When the amount of water injected is more than the standard amount of water, then it is easy to cause more steaming liquid to flow into the pot prematurely. When the ratio of powder to water is constant, the subsequent water injection will be less than planned, and the flavor of the coffee will be sour and the taste will be thinner.

When the steaming time is short, the carbon dioxide in the coffee powder is not fully discharged. If you find that there are large bubbles gushing from the powder layer in the water injection after steaming, it means that the steaming is not enough. The unemitted gas will hinder the extraction of flavor substances, and the gushing bubbles will also interfere with the extraction. In this case, the coffee will have a green and sour flavor. When steaming for a long time, the water on the surface of the coffee powder layer (hamburger) will slowly sink, leaving the expanded coffee powder, and a very large gap will be formed between the coffee powder after the loss of water, and a hole will appear when the water is injected continuously. then some rougher coffee foam appeared. If you see this, it shows that the steaming time is too long. In this case, the coffee is prone to bitter tail rhyme, the sweet and sour taste is not obvious.

With regard to the method of steaming and injecting water, Qianjie recommends that beginners use this method when steaming and injecting water until the surface of the coffee powder is wet. This way of injecting water is the easiest way to wet the coffee powder layer.