Is the steaming time of hand-brewed coffee calculated from the beginning of water filling or the end of water filling? Does stewing while making coffee count for a while?

"so first of all, let's pour twice the amount of water into the powder and steam it for 30 seconds." This is a step that must be carried out at the beginning of cooking in Qianjie-steaming. Under no special circumstances, this step must exist in the brewing process, because steaming makes it easier for us to make a good cup of coffee.

In fact, many friends have been very curious, why the time of steaming must be 30 seconds, must use twice the amount of water powder. Can't it take a longer time and shorter time, more water and less water? Yes, of course! In fact, the time and amount of water used in steaming is not required to be limited to which standard, of course, we are free to control the value used. However, before changing the parameters, we need to know what the role of steaming is, and then why should we recommend these two values, so that we can know when to adjust the time and when to adjust the amount of water.

The first purpose of steaming: exhaust is well known, the main purpose of steaming is to let coffee powder exhaust! After the coffee beans are roasted, there will be a large amount of carbon dioxide accumulated in the coffee beans. These carbon dioxide have both advantages and disadvantages: the advantage is that they can slow down the loss of coffee flavor substances, making the coffee beans taste longer; the downside is that when brewing, the presence of these carbon dioxide hinders the extraction of flavor substances by hot water. It is like a wall, blocking the demand for flavor substances from the outside world.

If we boil the beans directly without exhaust when the beans are relatively fresh, the hot water will be blocked by carbon dioxide so that the extracted material is not so high. In a special experiment conducted in Qianjie, the same beans used the same extraction parameters (the cooking time was also controlled at two minutes). The only difference was whether they were steamed or not.

The extraction rate of the pot of coffee without steaming is 13.53%, while that of the pot of steamed coffee is 17%. We can see how much the effect of carbon dioxide on the extraction is. Therefore, we need to steam this step to release the carbon dioxide that hinders the extraction of coffee powder. So why do we need 30 seconds for steaming?

In fact, there is no mandatory requirement for steaming for 30 seconds, such as 25 or 35 seconds. But relatively speaking, 30 seconds of this time will have a wider applicability, no matter what period of coffee beans, can carry out a relatively adequate exhaust. If the steaming time is less than 30 seconds, for some fresh coffee beans, the exhaust may be insufficient due to too much gas, which will affect the extraction; and if it is more than 30 seconds, the coffee powder will still exhaust, but the effect is not as good as before, and the exhaust speed will slow down a lot. Therefore, 30 seconds is a relatively safe exhaust time, neither the exhaust of coffee powder is insufficient, nor will it waste too much time on steaming.

Under what circumstances should you use other time for steaming? Quite simply, when there is too much or too little carbon dioxide. If the coffee beans are too fresh and contain a lot of carbon dioxide, 30 seconds may not be enough for the coffee powder to be fully vented. Therefore, we can appropriately extend the time for 5 seconds, so that the coffee powder emits more carbon dioxide, and the hot water injected later can better dissolve the flavor of the coffee. When the coffee beans are not so fresh and there is not so much carbon dioxide, we don't need to spend too much time steaming, just reduce the steaming time according to the wet state of the powder bed (about 5 seconds).

The second purpose of steaming: the second function of steaming is to infiltrate the coffee powder to form a link between the powder and the powder to reduce the uneven extraction caused by the existence of channels in subsequent extraction. But as we all know, the main purpose of steaming is to exhaust gas and pave the way for subsequent extraction. So at this time, if too much hot water is used for infiltration, then compared with the same period, this part of hot water will bring out less material than when it was placed in the main extraction.

Because the coffee powder has not been discharged at this time, hot water can not be fully extracted. Therefore, we need to reduce the amount of water used in steaming as much as possible. But the endless reduction will only prevent the coffee powder from being completely infiltrated, especially the lower the coffee powder is at the bottom of the filter cup. Therefore, at this time, our requirement for the amount of steaming water is: less, but not too little. It just so happens that dry coffee powder will absorb a certain amount of water, so people think that using this amount of water for steaming can effectively reduce the waste of hot water and make the coffee powder fully infiltrated.

Just like time, the amount of steam is only a relatively reasonable parameter, which is not fixed, and we can adjust it according to the state of the beans! However, there is no need to deliberately adjust, because the amount of water used for steaming is actually quite appropriate. Unless we are beginners who are unable to use this small amount of hot water to fully soak the coffee powder in the filter cup because the technology is not up to standard, then we can appropriately increase the amount of steaming water around 10ml.

-END-