How to make the steamed burger bulge when rushing? What is the difference between lightly baked beans and deeply baked beans? What determines the fat of coffee beans?

When we make hand-brewed coffee, in addition to the deep powder pit revealed when brewing is finished, the rapidly expanding "hamburger" when steaming is also a very healing sight.

But often, a lot of time the steaming can not produce a "hamburger". Either the drum bag is not prominent, or it is flat, or even it will sink down! And this kind of powder bed that does not bulge is often ridiculed as "Wotou"!

Then what on earth is the reason that will lead to steaming without bulging? We might as well take a look at the purpose of steaming.

The main purpose of this step is to release the carbon dioxide hidden in the coffee, so as to reduce the hindrance of extraction and make the subsequent injection of hot water better extract the aromatic substances in the coffee. When hot water is injected, all this carbon dioxide will be discharged because of "stimulation", but there is oil from coffee beans on the outside. As a result, the carbon dioxide forms countless bubbles under the wrapping of grease. The drum bag / "hamburger" is the image created by the coffee powder supported by these bubbles.

So we can know that the main factor that makes up the drum bag is carbon dioxide! The more carbon dioxide, the bigger the hamburger can be formed during steaming. The less carbon dioxide, the smaller the bulging bag. So you might as well guess what will lead to a reduction in the amount of carbon dioxide, resulting in the inability to swell larger "hamburgers" during steaming.

What is the reason why the powder bed can not bulge the "hamburger"?

First, although the coffee beans are not fresh, the coffee beans are not ground into coffee powder, but the carbon dioxide in the body will continue to be lost. The longer the coffee beans are stored, the less carbon dioxide they contain.

When the loss of carbon dioxide to a certain extent, the remaining bubbles have been unable to form a full "hamburger", so there is either "Hirakawa", or the drum bag is sunken. Second, when there is no hindrance of carbon dioxide, the flavor substances in the coffee will also lose the hindrance and accelerate the loss. So that's why we need to drink fresh coffee beans. Not only can it be well watched when steaming, but also the taste will be richer!

Second, the extraction efficiency is too low. The extraction efficiency, which is often said in Qianjie, refers to the difficulty of water extraction of substances in coffee! The higher the extraction efficiency, the easier it will be for water to extract substances from coffee, including carbon dioxide! In the production of hand-brewed coffee, the parameters that determine the extraction efficiency are the water temperature and the degree of grinding. Therefore, when our water temperature is too low to quickly bring out the flavor substances in the coffee, there will be a situation where the "hamburger" bulges smaller. In addition, it will easily lead to deficiencies in extraction, which will be more worthy of everyone's attention. Grinding is the same! When the coffee beans are ground too coarse, the total surface area is greatly reduced! It takes more time for hot water to enter the inside of the coffee powder and extract the substance from the body. This will also lead to smaller drum bags formed during steaming. Not only that, but also because of the increase in the gap between powder and powder, the hot water will slip away faster, which can also easily lead to insufficient extraction of coffee!

The degree of baking, of course, not all coffee will bulge larger "hamburgers" when steaming! What determines the content of carbon dioxide is the roasting degree of coffee beans! The deeper the roasting, the looser the structure of the coffee beans and the more carbon dioxide (and grease) they can store. The shallower the baking, the less carbon dioxide (and the less oil that spills over the bean surface).

Therefore, even if your coffee beans are very fresh, the extraction efficiency is also very rich, but because the roasting is too shallow, the drum bag is not obvious enough. Having said so much, Qianjie still wants to mention that the drum bag during steaming can only be used as a criterion for judging the freshness and roasting degree of coffee beans! It is not that the bigger the drum, the fuller the better. How does it taste? that's the most important thing.

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Front Street Cafe

No. 10 Baoqian street, Yandun road, Dongshankou, Yuexiu district, Guangzhou, Guangdong province