SCA gold cup extraction standard | what is the theoretical calculation formula of hand coffee gold cup?

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Gold cup extraction is a universal coffee extraction template, and Qianjie Coffee believes that gold cup extraction is an indicator symbol for the coffee industry, so what is gold cup extraction? What is its theoretical calculation formula? Next, Qianjie Coffee will give you popular science through this article.

What is gold cup extraction?

According to Qianjie Coffee, the Golden Cup Criterion is that in the 1950s, the National Coffee Association (NCA) hired Lockhart, a doctor of chemistry from the Massachusetts Institute of Technology, to study the scientific research of coffee. Gold cup extraction is simply to control the "concentration" in the process of making hand-brewed coffee between 1.15% and 1.45%. If the "extraction rate" reaches 18-22%, it is considered to be in the range of gold cup extraction. When we produce Qianjie coffee, we will also finish the product after the concentration and extraction rate reach the standard. Qianjie Coffee feels that there are many decisive factors before making a good cup of coffee, so what Qianjie Coffee can decide is to use its own professional skills to extract all the good flavors of this cup of coffee.

What is the formula for calculating the extraction rate of coffee?

Generally speaking, the extraction rate = coffee liquid quantity × coffee concentration / coffee powder quantity, but different countries have different gold cup extraction criteria. The following are the national coffee bean extraction standards for Qianjie coffee finishing:

American Fine Coffee Association (SCAA):

Extraction rate [18% Mel 22%] concentration [1.15% Mel 1.35%]

European Fine Coffee Association (SCAE):

Extraction rate [18% Mel 22%] concentration [1.2% Mel 1.45%]

Norwegian Coffee Association (NCA):

Extraction rate [18% Mel 22%] concentration [1.3% Mel 1.55%]

Brazilian Coffee Association (ABIC):

Extraction rate [18% Mel 22%] concentration [2% Mel 2.4%]

As can be seen from the above, the definition of the golden cup criterion is different in different countries, and the concentration demand for coffee is different in different countries, but the only certainty is that at present, it is generally believed that the coffee extraction rate is 18%, 22%, and the extracted coffee substance is delicious.

The most famous gold cup extraction criterion is the gold cup extraction chart, where the subscript axis represents the extraction rate of coffee powder, the left axis represents the concentration of coffee liquid, and the diagonal line indicates the ratio of powder to water (powder / water).

[concentration] indicates the proportion of "extracted coffee substance" to the total coffee liquid in a cup of coffee. [extraction rate] indicates the proportion of "extracted coffee substance" to the total weight of coffee beans.

Insufficient extraction means that the extraction rate is less than 18%, and over extraction means that the extraction rate is more than 22%.

Qianjie coffee is according to this range, to regulate our brewing parameters, every time there are new beans on the shelf, will go through the adjustment of roasting, cup testing, hand brewing and other links, in which the adjustment direction is to look at the TDS concentration, of course, usually drink coffee at home, it is not necessary to buy special equipment, according to the taste to judge the intensity.

However, coffee lovers who pay attention to precision might as well buy a special instrument to measure it. This instrument was invented by Vince Fedele, president of VST Company of the United States in 2008. It only needs to drop 2ml of cooling coffee liquid on the optical instrument to accurately read the coffee concentration value, which is very convenient. You don't have to use an oven to dry the coffee liquid or coffee grounds, as in the past, avoiding the tedious coffee concentration algorithm. (the instrument is shown below)

If there is no VST as an auxiliary measuring device, the calculation of extraction rate is much more complicated. At first, in the simplest way of making steel, Dr. Lockhart brewed coffee in an American coffee machine, wrote down the milliliters of black coffee, poured it into a metal vessel and put it in the oven to completely dry the water. at the end of the container, there is only solid powder left in the container. this is the coffee solid flavor extracted (hot water soluble substance), which divides the weight of the soluble substance by the weight of the coffee powder used to obtain the extraction rate.

The above is the gold cup theoretical calculation formula and related knowledge about gold cup extraction arranged by Qianjie Coffee, at the same time, this extraction rate is also suitable for hand-brewed coffee, then Qianjie Coffee will be demonstrated with Ethiopia Sakui 4.0, first of all, the following items need to be prepared: making a cup of hand-brewed coffee, coffee concentration tester (ExtractMojo), titration test tube, clear water.

Qianjie Coffee Ethiopia Sidamo Sakuran 4.0 Coffee beans

Country: Ethiopia

Producing area: Sidamo

Altitude: 2250-2350m

Variety: native species

Treatment: sun treatment

Flavor: rose, cream strawberry, citrus, passion fruit, oolong tea

Cooking scheme:

Powder content: 15g

Powder / water ratio: 1:15

Degree of grinding: fine grinding (the pass rate of No. 20 standard screen is 80%)

Water temperature: 91 degrees Celsius

Filter cup: V60

The cooking process is as follows:

The first stage is filled with 30 grams of water and steamed for 30 seconds.

The second stage is injected with 95 grams (the electronic scale shows about 125 grams), and the injection is completed in about 1 minute, with an interval of ten seconds.

The third stage is injected with the remaining 100 grams (about 225 grams shown by the electronic scale), and the injection is completed in about 1 minute and 40 seconds.

The drip filtration is completed in about 2 minutes. Remove the filter cup and complete the extraction.

How to determine the coffee concentration?

First of all, calibrate the concentration tester and clear the zero standard with pure water. Then stir the finished hand punch, and use the titration test tube to extract the coffee liquid, put it into the coffee concentration tester, press the determination key, try to determine the value many times, until the value is stable.

How to calculate the extraction rate of coffee?

Through the definition of concentration, we can know that the concentration is equal to the ratio of the weight of the extracted substance to the coffee liquid, and the extraction rate is equal to the ratio of the weight of the extracted substance to the weight of coffee beans.

Then the conversion formula can be obtained that the extraction rate is equal to the product of the concentration and the weight of the coffee liquid divided by the weight of the coffee bean.

Here Qianjie coffee generally assumes that the water absorption rate of coffee powder is 1:2, so we roughly get that the amount of coffee liquid is 225-(15 × 2) = 195g and the measured concentration is 1.45%, then the extraction rate is 1.45% × 195 / 1515g 18.85%.

From this Qianjie coffee can be concluded that this cup is a hand-brewed coffee with a concentration of 1.45% and an extraction rate of 18.85%. Therefore, it can be judged that this is a cup of hand-brewed coffee with high concentration and moderate extraction rate, and other factors such as this data and ratio can be used to adjust the coffee extraction concentration.

Of course, the Golden Cup is only a system for reference. After all, everyone has different tastes, and hand-brewed coffee that meets the golden cup data does not necessarily mean good coffee, so Qianjie Coffee suggests that we should try more. Drinking more is the more recommended practice.

In addition, the powder-to-water ratio of hand-brewed coffee also has a great influence on the extraction of coffee concentration. if the proportion of water is too large, the extraction concentration will be insufficient, and there will be no atmosphere together. On the contrary, if there is less water, the coffee will be over-extracted, and the coffee will become bitter. So Qianjie coffee also determines the powder-to-water ratio of hand-brewed coffee through hand-brewing practice, so let's share it with you below!

Proportion of hand-brewed coffee powder

As mentioned above in Qianjie Coffee, according to the sca gold cup extraction theory, the differences in the extraction parameters of gouache ratio of hand-brewed coffee are as follows:

[heavy flavour] 1-14-5-1-1-11-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-8-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-8-1-1-1-1-1-1-1-1

The specific brewing volume of coffee beans is 14.5 grams of water, which is 15.5. It is easiest to reach the golden range of 18% 22% of gold cup extraction rate and 1.15% of 1.35% concentration, which is why Qianjie coffee has been recommended to be brewed at 1:15.

This parameter was determined because it had been verified many times before, and although 1:12-1:15 was only the recommended range, Qianjie Coffee tested several parameters that were no longer in that range. The drip filter coffee with the ratio of powder to water at 1:20 tastes very light, but it will be very strong at 1:10. Through the adjustment test, 1:15 is Qianjie coffee that is thought to be more suitable for brewing most coffee beans. Of course, some people will use 1:14 or 1:17. These are all OK, the key depends on whether they can accept it or not. Qianjie coffee provides only a parameter acceptable to the public, which we can do for reference.

After determining the ratio of powder to water, then determine the amount of powder. One serving of Qianjie coffee is 15g powder, the amount of water is 225g, and the quantity is exactly one person.

The above is the relevant content of Qianjie Coffee about the standard gouache ratio of gold cup extraction of hand-brewed coffee, hoping to help coffee lovers understand more about it, so that they can have more theoretical knowledge to practice hand-brewing coffee in the future.

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