The Best question and answer Collection of Coffee extraction

Follow the caf é (Wechat official account vdailycom) and found that Beautiful Cafe opened a small shop of its own.

Many friends found that their coffee tastes different each time, so they asked: when the coffee is extracted, what is the concentration standard? In the way of coffee extraction, which is the more correct way of extraction? What is incorrect extraction?

The concentration of coffee bean extraction

First of all, it is important to know that no coffee bean can be completely extracted into coffee liquid, because only 30% of the substances in a coffee bean can be extracted, and the remaining 70% are insoluble wood fibers.

As far as the extraction standard is concerned, the "Golden Cup extraction Theory" issued by the former SCAA organization stipulates that the real extraction rate of a cup of coffee should reach 18%. 22% is the best extraction standard, while the concentration of "substances extracted from coffee" in a cup of coffee is only 1.15%. 1.35% (not surprisingly, about 98% of the coffee we drink is water) So it's not best to extract 30% of the water-soluble substances in every coffee bean.

However, the seemingly high concentration of espresso and the relatively strong coffee liquid produced by the mocha pot can not reach the level of "complete extraction", and their extraction rate will be in the range of 18% 22%. Because the "strong" of espresso only greatly reduces the proportion of water in a cup of coffee, after all, a cup of espresso only has a capacity of dozens of milliliters.

Gold cup extraction theory

Moreover, a cup of Italian concentrate often takes only a few seconds to get a cup of coffee with a very high concentration, thanks to its nine atmospheric pressure and high temperature extraction process. Hand-brewed coffee is controlled by the size of the water flow, the precise control of temperature and the degree of stirring (there is no doubt that drawing a circle clockwise during extraction is stirring) to control the extraction rate. as long as the extraction rate and concentration reach 18% 22% and 1.15% respectively, it is a good cup of coffee that conforms to the "golden cup extraction theory".

In order to achieve this goal, hand brewing requires the accumulation of time and experience, a serious and pious attitude towards hand brewing coffee, the control of various data, and so on. But must not pursue "complete extraction", not all the substances in coffee are aromatic substances!

Here is SCAA's "Gold Cup extraction Theory Chart".

How to adjust the concentration?

Adjust the ratio of powder to water (when other conditions are constant, if there is more powder and less water, the concentration will be high; if there is less powder, the concentration will be low.)

Questions that people often misunderstand:

"this cup of coffee is so bitter and exciting that it is overextracted!"

Case 1: this cup of coffee is overextracted. (the extraction rate is over 22%)

Case 2: the extraction rate of this cup of coffee is normal (18-22%), but the concentration is too high. This will also show the characteristics of bitterness and excitement. In this case, as long as you add the right amount of water to the coffee and adjust the concentration of the coffee to normal, the taste of the coffee will change greatly and may immediately become balanced and soft. In fact, what we are adjusting is the ratio of powder to water.

Case 3: this cup of coffee is too little extracted (less than 18%), but the concentration is too high. This will also show the characteristics of bitterness and excitement. In this case, the timely addition of water to adjust the concentration of coffee, the taste characteristics of coffee will not be very balanced, there will still be insufficient sweetness.

"this cup of coffee is so light that it doesn't seem to be extracted enough."

Case 1: this cup of coffee is extracted too little. (the extraction rate is less than 18%)

Case 2: the extraction rate of this cup of coffee is normal (18-22%), but the concentration is too low. In this case, the coffee may not have obvious characteristics, but it will not have a bad taste and flavor.

Case 3: this cup of coffee is overextracted (more than 22%), but the concentration is too high. In this case, the coffee will still show the characteristics of over-extraction, can drink a faint bitter taste or unpleasant miscellaneous taste.

"this coffee tastes bitter and is overextracted."

Case 1: it is over-extracted and the bitterness is obvious.

Case 2: too little coffee is extracted, all the sweetness is not enough, so the bitterness is more obvious.

The above situation can be summed up in two sentences: high concentration is not necessarily over-extraction; coffee bitterness is not necessarily over-extraction.