What exactly does the golden cup extraction of coffee mean?

The word "Golden Cup extraction" is often quoted in the articles in Qianjie, and some friends will leave messages in the background, asking what this "Golden Cup extraction" means.

Gold cup extraction, the so-called gold cup extraction, refers to the concentration and extraction rate of a cup of coffee as a reference to determine whether the cup of coffee has been fully extracted. The current gold cup value standard: the extraction rate is in the range of 18% Mel 22%, and the concentration is in the range of 1.15% Mel 1.35%.

The concept originated in the United States in 1952, when the American Coffee Association joined hands with Doctor Lockhart of the Massachusetts Institute of Technology to study and promote the coffee industry, and specially set up a coffee brewing committee (Brewing Committee). Professor Lockhart and his team studied the structure and chemical composition of coffee beans and found that coffee beans contained 30% soluble matter and 70% insoluble fiber.

They then immediately acted on the discovery: sampling coffee preferences among random Americans. The coffee extraction rate summarized in this survey is in the range of 21.2%, and the concentration is in the range of 1.04%, 1.39%, thus forming the initial gold cup extraction range. But at that time, hand-brewed coffee was not popular in the United States, so the test used a thicker grinding degree and a high water temperature to brew coffee, and the extraction time would go to about 4-8 minutes. It can be seen that there was a lot of instability in both people and coffee at that time.

So after that, the professional institutions carried out a number of careful dialectics, as well as many tasting by experts, and finally corrected the numerical range of the Golden Cup. The extraction rate is raised to 18% Mel 22%, while the concentration is in the 1.15% Mel 1.35% range. The gold cup extraction obtained this time has been recognized by the American Fine Coffee Association (SCAA) and has been in use ever since. A friend is about to ask: what is the concentration? What is the extraction rate? Gold cup extraction diagram We can observe the gold cup extraction diagram below in order to better absorb and understand the gold cup extraction theory.

The horizontal axis refers to the extraction rate, and the vertical axis refers to the concentration concentration, which means that we have more or less extract in a cup of coffee, the more, the stronger, the less, the lighter. The extraction rate refers to the percentage of soluble matter to coffee powder that can be obtained in this cup of coffee. We can get the concentration value from the coffee concentration meter, and then use the formula of "coffee liquid quantity ✖️ coffee concentration ➗ coffee powder quantity" to get the extraction rate.

By the way: there are diagonal lines in the gold cup extraction diagram, which represent the ratio of powder to water, that is, the proportion of coffee powder used in a cup of coffee and the corresponding hot water. The upper left corner of the picture is marked with a string of English, which probably tells us that each slash uses 1.9 liters of water, which corresponds to the amount of powder on the opposite side of the diagonal.

So we can do a shallow calculation: 1900ml ➗ 135g=14.07, which shows that the powder-to-water ratio of the first slash is 1135g=14.07 14.07. And so on, until the third slash just steps into the dark area of the picture.

This dark area refers to the ideal area where a cup of coffee can be extracted, which is what we call the gold cup extraction range; the extraction rate is 18%, 22%, direct, and the concentration is 1.2%, 1.45%. Coffee beyond this range is overextracted, while those that fail to reach this area are underextracted.

But this picture is easily misleading, that is, as long as you choose the diagonal powder-to-water ratio that enters the range of gold cup extraction, you will certainly be able to make a good "golden cup of coffee".

No, the powder-to-water ratio in the picture that reaches the gold cup extraction range does not necessarily mean that it is delicious when you rush out. It is only a reference to the data. What I want to express is that this powder-water ratio is easier to flush in the gold cup extraction range.

We learn the theory of gold cup extraction because it can help us better understand the extraction and change the improper cooking factors, thus rushing out the taste we want. Therefore, we can not misunderstand the concept of gold cup extraction, limited to the golden ratio of powder to water.

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