Introduction to Golden Cup Extraction Rate Theory for Pour-Over Coffee | How to Calculate Pour-Over Coffee Extraction Rate Tutorial

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/ The Golden Cup Theory of Coffee /

Now let's begin with practical application, starting with the calculation of extraction rate for pour-over methods.

Some people might wonder why we need to discuss extraction rates for different brewing methods separately.

In the world of coffee, standards are extremely important. They serve as a measuring stick, providing new coffee enthusiasts with a good reference benchmark.

All coffee experiments, barista preparations, and other activities at FrontStreet Coffee are based on the Golden Cup theory as our foundation.

However, this is only a reference and doesn't represent absolute correctness.

FrontStreet Coffee believes that if coffee has been extracted within the "Golden Cup" range, but the taste and flavor aren't particularly good, then there's no need to rigidly follow the theory. Appropriate flexibility allows customers at FrontStreet Coffee to enjoy coffee they truly love.

FrontStreet Coffee believes that whether for shop preparations or competitions, we should strive to develop our own brewing methods that allow each coffee to showcase its unique characteristics.

Therefore, we need to understand the flavors of different coffees and comprehend what changes occur during different extraction stages. What differences will there be in concentration and taste? All of these are extremely important considerations.

/ Coffee Extraction Fundamentals /

Coffee beans are not entirely water-soluble. In a single coffee bean, only 30% of the substances can dissolve in water, while the remaining 70% consists of insoluble materials like woody fiber.

Therefore, the maximum extraction rate for coffee is only 30%. Among the water-soluble substances, there are some that we prefer not to have in the final brewed coffee. (Such a dilemma!)

What we call extraction rate refers to the proportion of coffee substances dissolved in water relative to the total coffee grounds used in extraction:

That is: Weight of dissolved coffee substances ÷ Weight of original coffee beans (grounds) = Extraction rate

(How's that? Not too confused, right? Haha, let's continue!)

For example:

If you use 15 grams of coffee grounds for brewing, then dry the used coffee grounds completely and weigh them at 12.3 grams, then the weight of substances dissolved in water would be 2.7 grams.

Therefore, the extraction rate of this coffee would be 2.7 ÷ 15 = 0.18 (18%).

The extraction rate calculation method we commonly use is related to coffee concentration.

Of course, for this calculation, we first need to prepare a concentration testing instrument (TDS meter).

/ Concentration and Extraction Rate /

Concentration represents the proportion of "extracted coffee substances" to the total coffee liquid in a cup.

Extraction Rate represents the proportion of "extracted coffee substances" to the total weight of coffee beans.

(One subject is coffee liquid, the other is coffee beans or coffee grounds)

The most famous aspect of Golden Cup extraction standards is the Golden Cup extraction chart. The horizontal axis represents the extraction rate of coffee grounds, the vertical axis represents the concentration of coffee liquid, and the diagonal lines represent the powder-to-water ratio (grounds/water).

Based on these conditions, we know:

Coffee liquid concentration = Weight of extracted coffee substances ÷ Weight of coffee liquid

Coffee extraction rate = Weight of extracted coffee substances ÷ Weight of coffee beans (grounds)

Combining the above formulas, we derive the calculation formula for coffee extraction rate:

Coffee extraction rate = Coffee liquid concentration × Coffee liquid weight ÷ Coffee bean (ground) weight

However, it's important to note that for drip coffee, the coffee grounds themselves absorb twice their weight in water, so:

Coffee liquid weight = Water amount - 2 × Coffee bean (ground) weight

For example:

If you use 15 grams of coffee grounds to brew coffee at a 1:16 grounds-to-water ratio, and measure its concentration as 1.37% using a concentration meter, then the extraction rate of this coffee would be 1.37% × (240 - 2 × 15) ÷ 15 = 19.18%

FrontStreet Coffee uses this range to standardize our brewing parameters.

Every time new beans are released, they go through adjustments in roasting, cupping, and pour-over processes. The direction for pour-over adjustments is determined by TDS concentration. If you're just casually enjoying coffee at home, there's no need to go through the trouble of buying specialized instruments (facepalm.jpg), you can judge the concentration based on your own taste preferences.

FrontStreet Coffee · Extended Reading

Different countries have different Golden Cup extraction standards. Below are the coffee bean extraction standards from various countries compiled by FrontStreet Coffee:

Specialty Coffee Association of America (SCAA)

Extraction Rate 【18%-22%】 Concentration 【1.15%-1.35%】

Specialty Coffee Association of Europe (SCAE):

Extraction Rate 【18%-22%】 Concentration 【1.2%-1.45%】

Norwegian Coffee Association (NCA):

Extraction Rate 【18%-22%】 Concentration 【1.3%-1.55%】

Brazilian Coffee Association (ABIC):

Extraction Rate 【18%-22%】 Concentration 【2%-2.4%】

From the above, we can see that different countries have slightly different definitions for Golden Cup standards. While countries have varying requirements for coffee concentration, the one certainty is that it's currently widely believed that coffee extraction rates between 18%-22% produce the most delicious extracted coffee substances.

/ What Constitutes Over-Extraction? /

I believe everyone has encountered this situation: after tasting a cup of coffee, exclaiming "This is bitter, it's over-extracted!"

FrontStreet Coffee believes that bitterness doesn't necessarily equal over-extraction.

Putting aside individual differences in sensitivity to bitterness, even when unusual burnt or bitter flavors appear in coffee, we can't blame everything on "over-extraction."

First, the term "over-extraction" is based on the Golden Cup standard, meaning exceeding the extraction range specified by Golden Cup guidelines.

The Golden Cup standard suggests that when coffee extraction rates fall within the 18-22% range, the extracted coffee substances are relatively delicious.

When exceeding 22%, it's possible to extract unpleasant bitter flavor substances.

Therefore, over-extraction essentially describes coffee with extraction rates exceeding 22%.

Coffees with extraction rates generally above 22% tend to exhibit burnt bitter flavors, and over time, bitterness and over-extraction became equated.

/ Practical Demonstration with Ethiopian Coffee /

This extraction rate also applies to pour-over coffee. Next, FrontStreet Coffee will demonstrate using Ethiopia Guji 4.0. You'll need to prepare the following items:

Equipment for making pour-over coffee, coffee concentration tester (ExtractMojo), titration tube, and clean water.

FrontStreet Coffee · Ethiopia Sidamo Guji 4.0 Coffee Beans

Country: Ethiopia | Region: Sidamo | Altitude: 2250-2350m

Variety: Local indigenous varieties | Processing: Natural

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

FrontStreet Coffee · Brewing Recipe

Coffee dose: 15g

Ratio: 1:15

Grind size: Fine (80% pass-through on #20 standard sieve)

Water temperature: 90°C

Dripper: V60

FrontStreet Coffee · Brewing Notes

First pour: Inject 30g of water for a 30-second bloom.

Second pour: Inject 95g (scale shows around 125g), completed in about 1 minute, with a 10-second interval.

Third pour: Inject remaining 100g (scale shows around 225g), completed in about 1 minute 40 seconds.

Drip filtration completes in about 2 minutes, remove the dripper, extraction complete.

/ How to Measure Coffee Concentration? /

• First calibrate the concentration tester, zeroing it with pure water;

• Stir and cool the freshly extracted coffee liquid, extract coffee liquid using a titration tube, and place it in the coffee concentration tester. The temperature must have cooled to room temperature;

• Press the measurement button, try measuring multiple times until the value stabilizes.

Here, FrontStreet Coffee typically assumes the coffee grounds' water absorption rate is 1:2.

So we roughly calculate the coffee liquid amount as 225 - (15 × 2) = 195g, measuring a concentration of 1.45%.

The extraction rate would be 1.45% × 195 ÷ 15 = 18.85%

From this, FrontStreet Coffee can determine that this is a pour-over coffee with 1.45% concentration and 18.85% extraction rate.

Therefore, we can judge this as a pour-over coffee with slightly high concentration and moderate extraction rate, and use this data along with ratios and other factors to adjust coffee extraction concentration.

Of course, Golden Cup is just a reference system. After all, everyone's taste is different.

Pour-over coffee that meets Golden Cup data doesn't necessarily represent delicious coffee.

Therefore, FrontStreet Coffee recommends that everyone try more and taste more - this is the more recommended approach.

Additionally, the pour-over coffee grounds-to-water ratio significantly affects coffee concentration extraction. If the water proportion is too high, the extraction concentration will be insufficient, and the taste will lack character;

Conversely, if there's too little water, it will lead to over-extraction, making the coffee bitter and difficult to drink. Therefore, FrontStreet Coffee has also determined the pour-over coffee grounds-to-water ratio through practical experience, which we'll share with you below!

/ Pour-over Coffee · Grounds-to-Water Ratio /

As mentioned above by FrontStreet Coffee, according to pour-over coffee water-to-ground ratio extraction parameters derived from SCA Golden Cup extraction theory, the taste differences are as follows:

Rich Flavor 1:10～1:11 (equivalent to Golden Cup standard 1:12.5～1:13.5)

Balanced Flavor 1:12～1:13 (equivalent to Golden Cup standard 1:14.5～1:15.5)

Light & Refreshing 1:14～1:16 (equivalent to Golden Cup standard 1:16.5～1:18.5)

Coffee bean weight to brewing water ratio of 1:14.5～1:15.5;

easily achieves the Golden Cup extraction rate of 18%～22% and concentration of 1.15%～1.35% golden range.

This is why FrontStreet Coffee always recommends using 1:15 for brewing.

The reason for determining this parameter is that multiple verifications have already been conducted. Although 1:12-1:15 is just a suggested range, FrontStreet Coffee still tested several parameters outside this range.

Drip coffee at 1:20 grounds-to-water ratio tastes very light, while 1:10 would be very strong;

Through adjustment experiments, 1:15 is what FrontStreet Coffee considers more suitable for brewing most coffee beans.

After determining the grounds-to-water ratio, determine the coffee dose.

FrontStreet Coffee's single serving is 15g of grounds with 225g of water, which is just right for one person.

The above is the content compiled by FrontStreet Coffee regarding pour-over coffee Golden Cup extraction standard water-to-ground ratios.

Of course, some friends prefer to use 1:14 or 1:17, etc. - these are all acceptable. The key is whether you personally find it acceptable.

What FrontStreet Coffee provides is just a generally acceptable parameter that everyone can use as reference.

We hope this helps coffee enthusiasts better understand related content.

For more specialty coffee beans, please add FrontStreet Coffee on WeChat: kaixinguoguo0925

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473