How does "steaming" affect the flavor of hand-brewed coffee?

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Bloom, the so-called steaming, is the pre-operation of soaking coffee powder with a small amount of hot water before making coffee. Roasted coffee beans gradually emit carbon dioxide through small holes in the surface. this process is called awakening or ripening, and the emission rate varies according to the degree of baking, and the exhaust slows down as time goes on. Steaming grasps the moment when hot water comes into contact with the powder to let the gas out quickly.

This seemingly simple small action has a great impact on the finished product. After grinding into coffee powder, the surface area of contact with the outside world increases greatly, and the gas begins to emit. These gases will form an isolation layer between hot water and powder and can not be extracted effectively. And carbon dioxide dissolves in water will have a sour taste, resulting in a bad taste. Infiltration makes the temperature rise and the gas is discharged upward, which makes the surface of the coffee powder protrude and expand as a whole. some people say that the protruding degree of the surface layer of coffee powder represents the freshness of coffee, but no matter whether it is formed or not and its size, the key point is whether the purpose of this action can be achieved.

The key point of steaming is to release the gas that will interfere with the manual extraction first, so as to make the extraction process more smoothly.

In addition to the exhaust, steaming takes away the gas while hot water fills the hole, and the contact between the powder and hot water makes the aroma disperse. in addition, the powder expands and expands the distance between them, and the circulating gas promotes the stretch. opening the pores between the powders makes it easier for water to pass, which is conducive to subsequent water flow control, which are the associated effects of exhaust gas.

Steaming well is like getting a ticket to make a good coffee, but some people find that the initial soaking leads to a bitter taste during the trial, one is that the soaking time is too long, the other may be that the force under the water injection is too small, causing the water to be blocked on the surface and unable to flow smoothly through the powder to be evenly absorbed, so how to make steaming really improve the overall quality needs in-depth understanding.

Three key points of steaming

Whether there is a good steaming effect can be divided into the following three points:

Water quantity

The handling of water depends on the amount that the powder will absorb, generally speaking, the powder will absorb about twice as much water, that is, 1 gram of powder will match 2 grams of water, this ratio can make the powder evenly infiltrated and not flow out too much extract. Too much water will cause the extraction to start early and affect the steaming structure system, and too little will make the powder unable to infiltrate completely. If there are still a large number of bubbles in the extraction, it may be a lack of water, and some parts are not soaked. It will make the extraction uneven taste imbalance, visual conditions to increase or reduce the amount of water.

Water temperature

When brewing coffee, the water temperature will affect the extraction rate, and then change the taste with time, the steaming water temperature is more important to the coffee quality than the control of the water temperature at the beginning of hand brewing, and it is also an important link in the whole process. Steaming is the beginning of the contact between water and powder, and whether the temperature is moderate or not is an important moment to affect the activation of the whole system.

Shallow, hard coffee beans exhaust slowly, will need higher temperature water to accelerate gas emissions, the general water temperature will be controlled at about 90 degrees, although the temperature is high, aroma is more obvious, but also bring out the risk of astringency. The deep-roasted and soft coffee beans are highly active and the gas can be discharged more easily, so the water temperature can be slightly lower than 90 degrees. Adjusting the water temperature according to the baking degree and quality of the beans can make the whole brewing process smoother and bring out the aroma, taste and consistency of the coffee stably.

time

The time of steaming is calculated from the end of water injection, and it is used from 20 seconds to about one minute. It mainly depends on the formation of the hamburger and whether the gas is discharged smoothly. 30 seconds to 40 seconds is a relatively common time, too long steaming will excite the coffee powder, bring out the subsequent bitterness and astringency, too short will infiltrate enough, there is no way to show the flavor.

The whole steaming process is to let the coffee powder fully infiltrate, gently inject the water and distribute evenly, and use the water temperature to activate the coffee powder to let the gas out. The reason for the use of fresh coffee powder can also be seen from the steaming. The fresh powder is highly active after discharging most of the gas in the soaking stage, which can make steaming play a good effect and lead to good coffee. Steaming is like an alarm clock to wake up coffee beans. "A good beginning is half done" is very suitable for steaming. Whether you can make the coffee powder live depends on the first half a minute.

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