Understanding the Concepts of Extraction and Strength in Coffee

The terms extraction and strength are often used in discussions about coffee. While their colloquial meanings may imply certain characteristics of coffee, it is important to understand their technical definitions in the context of coffee brewing. This article aims to provide a concise and academic explanation of these terms, drawing on insights from reputable sources such as Coffee Stack Exchange and Helena Coffee Vietnam.

Extraction

Extraction refers to the amount of soluble substances in coffee that are released during the brewing process. It quantifies the proportion of the coffee mass that ends up in the final brewed coffee. According to the Specialty Coffee Association (SCA), the recommended extraction range is between 18% and 22%. If the extraction level falls below 18%, the coffee is considered under-extracted, resulting in a sour taste. Conversely, extraction levels above 22% are considered over-extracted, resulting in a bitter flavor profile.

Strength

Strength in coffee refers to the concentration of dissolved solids in the coffee beverage. It measures the amount of coffee present per unit of water and indicates the intensity of the flavor. The solubility of coffee determines its strength, with espresso typically having a solubility range of 8% to 11%. This means that 8% to 11% of the cup is dissolved coffee solids, while the remaining portion is water. Manual brewing methods, on the other hand, have a lower solubility of about 1% to 1.5%, resulting in a lower coffee strength.

Relationship Between Extraction and Strength

It is important to note that extraction and strength are two different concepts in coffee brewing. While extraction refers to the amount of dissolved substances, strength focuses on the concentration of these substances in the beverage. High extraction does not necessarily indicate strong coffee, as strength depends on the ratio of dissolved solids to water. A cup of espresso, despite having a higher extraction percentage, can be significantly stronger than a hand-brewed coffee due to its higher solubility.

Conclusion

In the realm of coffee brewing, extraction and strength have specific technical meanings. Extraction quantifies the amount of soluble substances extracted from the coffee grounds, while strength measures the concentration of these substances in the final beverage. Understanding these terms is essential to achieving desired flavor profiles and making informed adjustments during the brewing process. By adhering to recommended extraction ranges and considering the solubility of coffee, baristas and coffee enthusiasts can produce balanced and flavorful cups of coffee.

FAQs

What do the terms extraction and strength mean?

There is a great misconception in the normal world of coffee (where 99.9% of the world lives), but first we should define the difference between strength and extraction. Strength is the concentration of coffee in the cup, whereas Extractions is the amount of soluble coffee matter dissolved from the bean/grounds.

What do you mean by strength of coffee?

Roast and Strength of Coffee Explained

If by strength you mean the amount of caffeine contained in a coffee, then the largest single influence is the amount of coffee dosed compared to the amount of water to make a cup of coffee.

What does extraction mean in coffee making?

the act of taking something out

Extraction as a word simply refers to the act of taking something out. In the case of coffee, the “extracting” that we’re referring to is the act of pulling soluble compounds out of coffee beans by using water. Pretty simple.

What is the ideal extraction rate for espresso coffee?

The standard brewing ratio is 1: 2. For every gram of ground coffee, two grams of espresso are extracted, so for example 18g of ground coffee should be 36g of espresso.

What is caffeine extraction?

Extraction is a technique in which a solvent is used to remove/isolate a compound of interest from a liquid substance. For example, coffee is a liquid which contains dissolved caffeine. The extraction will be carried out by simply adding a portion of solvent to the coffee.

How is coffee strength measured?

We can measure strength in coffee using a refractometer and refer to strength using TDS (Total dissolved solids). For espresso brewing, there is a large window of 8% – 12% TDS. The significance of these numbers will become more apparent as you read on.

Which coffee type is strongest?

The most concentrated coffee type is a ristretto – this contains relatively the highest level of caffeine. However, a lungo is larger and thus contains more caffeine than a ristretto. Based on concentration levels of caffeine, these would be the strongest coffee types: RISTRETTO.

What is the best extraction for coffee?

The “ideal” water temperature to make coffee is around 195–205℉ (around 91–96 ℃). This is just under boiling and is the point at which most flavour compounds easily dissolve in water. The higher the temperature of the water, the more quickly extraction will happen. If water is too cool, extraction takes much longer.

What type of extraction is coffee?

Coffee extraction occurs when hot water is poured over coffee grounds, causing desirable compounds such as caffeine, carbohydrates, lipids, melanoidins and acids to be extracted from the grounds.