As an important step in brewing coffee, there are also rumors in the market that "whether the coffee is good or not, you can know it by looking at the steaming state". Therefore, when everyone learns to make coffee, they consciously or unconsciously "practice" a perfect "coffee burger". But if you understand the logic behind stuffy steaming, you will find that stuffy steaming is so simple. Why is brewed coffee simmering? **The most direct way to this problem is to skip the steaming step of the hand-poured coffee for comparison, it is not difficult to find that if it is not steamed, when pouring water to brew, there will be bubbles constantly emerging from the powder layer, and when comparing the coffee flavor, the coffee that is not stuffy is obviously thin, watery, and the taste is also very light.
And these bubbles are the "culprits" that cause the poor flavor of this cup of coffee. These bubbles are actually the carbon dioxide in the coffee beans, and when the coffee beans are freshly roasted, they will be rich in carbon dioxide, which can usually inhibit the loss of flavor, and will also inhibit the release of flavor substances during brewing. Therefore, during the brewing process, the carbon dioxide is expelled first by steaming and then extracted.
The "coffee burger" that appears when steaming is because when the coffee powder absorbs water, carbon dioxide will be squeezed out, and when a lot of carbon dioxide is emitted at the same time, because the gap between the coffee powder is too small, these gases have nowhere to come out, so they will prop up the coffee powder layer and find a channel to discharge.
Front Street doesn't find out when smoldering appeared, but we know that smoldering is used to expel carbon dioxide, which is only found in fresh coffee beans. So the first method of steaming must have been to have a local roast of coffee.
At a time when the concept of focusing on fresh roasting coffee beans was not yet formed, freshly roasted coffee was not good because its extraction taste was not as stable as that of long-aged coffee beans. In the field of hand pouring, some people have noticed this instability** when the beans emit gas during brewing, and when there is less gas, the more stable the coffee taste.
Then came the emergence of various punching methods that avoided gas interference in the extraction. For example, it is most common to inject a small amount of water, wait for a while, and let the gas drain before filling the water. There is also a dripping form to slowly soak the ground coffee when the gas has enough time to expel it. Although their methods vary, they essentially use as little water as possible to get the gas out.
Later, a simple steaming method slowly evolved, which is to simmer twice the amount of water for 30 seconds. There are two parameters involved here, the amount of steaming volume and the steaming time. The reason why twice the amount of water is used for smoldering is because the ground coffee can only absorb twice the amount of water itself, and any amount of water is wasted. The smothering time is to observe that most of the coffee beans are almost exhausted in about 30 seconds. After summarizing this conclusion, it is possible for some novice enthusiasts who do not know the principle to brew a good tasting coffee according to this method.
But when you understand the function and principle of steaming, you will know that steaming is nothing more than soaking the coffee ground completely, and then allowing enough time for it to release gas.
Then you can set the amount and time of simmering according to the actual state of the ground coffee. For example, the water absorption of dark roasted coffee beans is better, and most of the water can be absorbed when steaming and pouring water, and only a little bit of coffee liquid is dripped into the pot in advance, so twice the amount of water is used; And there are some shallow roasted coffee with a particularly hard hardness, which has poor water absorption, and a lot of it drips into the lower pot, so you can use a little less water to steam, such as 15-1.7 times the amount of water.
At the same time, whether the steaming is good or not also depends on the water injection method, and the front street is generally recommended to inject water into the center in a small circle outward, so as to avoid some water flowing directly from the side of the filter cup. But also be careful to make sure that the ground coffee is soaked to the point that there is no dry ground coffee at least on the surface.
Some coffee grounds don't swell so much more, so you need to circle a little more when you pour water, and these practices will feel good a few times. Some friends pay too much attention to the amount of water and time of steaming, but its water control ability needs to be improved, after the amount of steaming is injected, there is also a powder layer is dry, so that the steaming is not thorough, and the coffee brewed out will not be too good. The advice given by Front Street is that if you really can't soak the ground coffee in twice as much water, then fill in more water, and remember that the purpose of steaming is to soak the ground coffee all and expel the gas.
Then there is the question of time, the amount of gas in the body of coffee beans varies depending on the roasting time period. For example, coffee beans 4 days after roasting and coffee beans 15 days after roasting will not expand to the same extent and gas emission activity will not be the same. Therefore, the steam time is determined according to the actual degree of gas emissions. For example, some coffee grounds are still expanding and exhausting after 30 seconds, so you need to wait for it to drain before filling water, and some are motionless for more than 20 seconds.
To sum up, the smothering step is very simple, which is to soak all the coffee grounds according to the planned amount of water, and then wait for the coffee burger to stabilize and then complete the smothering stage, and the rest is the extraction stage.
Finally, let's talk about it, "whether the coffee is good or not, just look at the steaming state" This sentence is not mainly to say whether you are steaming and filling water well, but to judge the freshness of the coffee beans by looking at the steaming state, if the gas is very active and bubbles, it means that it is too fresh, and there may be dryness and astringency; If it swells evenly and there are no rapid bubbles coming out, it means that the beans are good and have been raised; If the simmering does not expand, it means that the beans are not fresh.
And this method is not entirely correct, first of all, some shallow-roasted coffee beans are hard and have a slower exhaust, so there is no obvious bulge. Many people will use whether the steaming is puffed up or not as the basis for the freshness of the coffee, and it is easy to misjudge here. Secondly, it is not that the coffee beans that can't be steamed are not delicious and not fresh, and Qianjie has also tested a lot of coffee beans that have passed for 1 month, and there are many coffee beans that have not changed when they are steamed, but the flavor and taste of the brew are not fresh, so it is still based on the actual situation.
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