Extraction methods and methods of coffee what is the extraction rate?

The taste and extraction methods of coffee are very diverse. The European Fine Coffee Association once put forward the concept of "Gold cup". A certain extraction rate and coffee concentration determine the taste of coffee, but what is the extraction rate, and what is its effect on the taste of coffee? First of all, the concentration represents the amount of soluble matter (TDS) in your cup of coffee, so: TDS%=TDS/Coffee Weight (CW) is very simple and clear, that is, the concentration represents the total weight of a cup of coffee. So the higher the concentration, the stronger your coffee. Generally speaking, the reason why we drink espresso is very strong, because its concentration is about 8% Mur11%, while filtered coffee is very light, because its concentration is about 1.15-1.4%.

There are many kinds of coffee extraction methods. Today, I would like to introduce several coffee extraction methods for you to learn.

What is the extraction rate?

Coffee beans cannot be 100% integrated into water, and soluble matter in coffee accounts for a percentage of coffee powder that was previously extracted. And to put it more colloquially, how much substance in coffee has been incorporated into the water. Therefore, the extraction rate is that there is a very important concept of TDS/DOSE (gram weight of powder). The reasonable extraction rate will be between 18% and 22%. If we extract too much, we will drink bitter and mixed-flavored coffee. If it is less than 18%, the coffee we often drink will be sour. It must be mentioned that whether it is espresso or filtered coffee, the extraction rate is in this category.

All modern coffee extraction is the two core processes of soaking and filtration, which belongs to the category of physics, and there is basically no chemical change in the process. The differences in the thickness of coffee powder, the length of soaking time, the method of separation and filtration, and so on, have created a wealth of coffee brewing utensils and techniques. Although the core process of coffee extraction is the same, according to the significant differences in pressure and time used in coffee extraction, modern coffee extraction methods can be simply divided into two types:

1: coffee machine extract coffee

(Espresso) is invented in Italy, at 9 atmospheric pressure, 92 degrees water temperature, 25 seconds to extract 30 ml of espresso; this is significantly different from other coffee extraction methods, unnatural conditions can be done, reflecting the intervention of science and technology. Espresso Espresso can generally be made by Italian semi-automatic coffee machine and full-automatic coffee machine. A good Espresso requires higher price and quality of coffee machine and bean grinder.

Espresso machine

When it comes to espresso machines, Italian roasted beans that are almost carbonized were used in the past. But now the mainstream is to use urban-deep urban baking that emphasizes aroma and sour taste (medium-deep baking). The grinding degree of coffee powder is extremely fine, and then extracted with hot water of about 92 ℃ and high pressure of 9 atmospheric pressure.

The turnover of general household disposable products, such as espresso filter bags or Nestl é capsule coffee machine K-CUP, is gradually rising, and you can taste good coffee at home even without the barista's technology. For an espresso machine, it may be a way to bring the dead back to life.

2: soak and extract coffee

It is a traditional, natural and simple way of coffee extraction; the extraction temperature is close to 85-92 and the filtration pressure is about 1 atmospheric pressure.

Can be subdivided into: filter paper drop method, French filter kettle, Saifeng kettle, Turkish coffee pot.

Filter paper filter drop method

The filter paper dripping filter method can make the beans present the original taste directly, and can correspond to various baking degrees. Just the operation process requires a little skill, for example, if the drip filter core, astringent strong coffee, it is necessary to use roughness grinding, so that hot water quickly through the coffee powder, more or less can be adjusted. Shorten the "stuffy steaming" process to make the overall taste lighter, but also can adjust the original taste is too strong, too bitter taste. The filter paper trickling filter method has this kind of variability. The most suitable degree of grinding is moderate grinding. It is inappropriate to be too thick or too thin. Pick up a pinch of coffee powder in your hand, which is best if it feels rough. The hot water temperature is about 82-83 ℃. There is no special skill in using filter paper to filter fine coffee. The aroma is more likely to escape than when extracting commercial coffee. After all, it is necessary to be exposed to external air, which can not be done, and may be the only weakness of the filter paper trickling method. In addition, it is easy to highlight some specific flavors when extracting at low temperature, so care must be taken. Fine coffee has no miscellaneous flavor, so it tastes good when it is cold.

French filter kettle

When using filter paper or flannel drip filter, coffee oil will be adsorbed on filter paper or flannel, but if you use a French filter kettle, it can be extracted together with oil, so coffee will have an oily taste, which is also a major feature of this extraction method. However, because of this slippery taste, the evaluation is quite polarized. Although it is difficult to adjust the taste of the details, you can still taste the unique sour taste and fragrance after a long time. Suitable for medium baking and roughness grinding. In terms of structure, the French filter kettle belongs to the "props with the dominant taste of materials". If you use good materials, you can clearly show your personality and be very interesting, but if the materials are not good, you will extract the disappointing taste. The key point is the strict selection of materials. It is generally believed that hot water can be used in French filter kettles, but in fact no one knows the truth. Some people only add half of the hot water, which is similar to the "steaming" of trickling filtration. The best extraction time is 4 minutes (note: the extraction time should be fine-tuned according to the grinding condition, the rough time is long, and the detailed time is short. In addition, it is also a short time to stir up the coffee powder. In addition, it is also important to actually stir up the coffee powder.) However, there are also suggestions that even impurities may be extracted after sitting for 4 minutes. This method of extraction uses hot water, and the aroma released is really strong.

Saifeng kettle

The Saifeng kettle is extracted at high temperature. (note: the temperature of the Saifeng kettle is not high, the upper kettle is about 90 ℃, it can't be higher.) Therefore, it is easy to produce aroma, but it is a big disadvantage that the taste is not as thick as that of drip filtration. Plus coffee powder soaked in hot water. Therefore, it is not easy to show subtle taste differences. However, the teapot is quite suitable for performance and display, so it may be just right for the promotion of boutique coffee. At present, the most popular coffee in the United States and other places is Saifeng pot coffee, which is heated by halogen lamps. Saifeng kettle has become a thing of the past in Japan, and it can hardly be seen recently. However, it is also a good thing that Saifeng kettle can follow the third wave and unwittingly become the new darling of the American coffee industry. The degree of grinding of coffee powder is the same as that of filter paper dripping filter. The baking degree is medium baking ~ medium depth baking. Saifeng kettle is a relatively stylized extraction method. Stirring at which time and leaving the fire at which time is the key. In addition, in order to avoid the temperature drop in the extraction process and accidentally cook miscellaneous smell, the firepower must be adjusted appropriately.

Turkish coffee pot

Turkish coffee using Turkish coffee pots is still widely loved by countries such as the Middle East, North Africa and Greece in the Balkans. Turkish coffee pots in the shape of spoons are mainly made of copper or brass. The way to use it is to put in coffee powder and sugar and then boil it with water. It can also be said to be the ancestor of boiling extraction. However, it is not popular in Japan. Taste the surface of the boiled coffee liquid is the most basic way to drink, and then enter the esoteric world, to be honest, I am not very clear. In spite of this, organizations such as SCAE (European boutique association) will hold activities such as the "World Turkish Coffee Championship", which may be richer in the future.