When you stop to think about it, a great cup of coffee is pretty amazing. At least a dozen factors can seriously influence its taste as it traveled thousands of miles over many months from seed to cup. When considering the hours and hours of careful, sometimes backbreaking, work that went into growing and processing a specialty coffee and then roasting and packaging it for distribution, proper brewing can be the most crucial step in ensuring that a customer gets a delicious cup of coffee. That’s because 100% of what a customer tastes in a cup of coffee is extracted through the brewing process.
Creating a masterpiece of coffee in a cup is no easy task. So Stockton Graham & Co. works with coffee shop owners, baristas and speciality beverage operators on several training modules designed to help brewers master the art of brewing coffee.
Each of these training modules is based on the six essentials to brewing coffee, created by the Specialty Coffee Association (SCAA), which address correct water-to-coffee ratio, proper brew method, proper equipment operation and other critical factors that effect coffee quality.
The success of your coffee shop hinges on the brewer’s understanding and mastery of these brewing skills. As an easy reference, Stockton Graham & Co. has created a summary booklet called BEAN Artist: The 6 Essentials of Brewing, which you can view here.
Balancing Extraction and Strength
There are two fundamental characteristics of a brewed cup of coffee that effect its flavor—Extraction and Strength. A barista who understands the six essentials of brewing is well on the way to mastering the fine balance between extraction and strength that will create the perfect cup.
EXTRACTION describes the process of pulling the flavor and essence from coffee. It occurs during the brewing process when water passes over and through coffee grounds, activating gases that have built up during roasting, releasing pleasing aromatics and dissolving all types of compounds that flow into a cup. Some of those elements taste great, but others are not so great. Getting the extraction just right—which means dissolving the right amount of the good-tasting compounds and minimizing the bad-tasting compounds—is as much of a skill as it is an art.
When a coffee is brewing, the first thing to come out of the grounds are gases that we can smell called aromatics. There are well over 800 different aromatics that can be detected by the human nose—some pleasant and some not-so-pleasant. Aromatics make up a very small volume of the total amount of extracted compounds but are responsible for most of the aroma.
The next elements that are extracted are called soluble compounds, meaning they dissolve in water. These include caffeine and soluble fibers like sucrose and pectin, which effect the flavor of the brewed coffee.
When it comes to optimizing a brew, it turns out that almost everyone prefers a cup of coffee brewed by stopping the extraction at around 20% of the total bean weight. This leaves the compounds that taste the worst—tannins that often lead to a bitter or astringent flavor—in the coffee filter with the grounds.
Of course, 20% is just an average. The Specialty Coffee Association recommends extraction rates fall between 18-22% of the total bean weight. Extract over 22% of a bean’s weight, and the coffee tastes bitter or astringent and is considered OVER-EXTRACTED or OVER-DEVELOPED. Extract less than 18% of the bean’s weight, and the coffee tastes watery and grassy to most people. This is referred to as UNDER-EXTRACTED or UNDER-DEVELOPED.
Coffee STRENGTH, which you can roughly determine by observing how much light passes through a cup of brewed coffee in a glass vessel, is a factor of the ratio of coffee to water in a brew. Some mass market coffees, especially those sold in the United Kingdom, use the word strength to describe the darkness of roast, with dark roasts scoring a 4 or 5 on the strength scale. Although roast levels do effect extraction and can impact the perception of a coffee’s strength, Stockton Graham & Co. uses the SCAA definition of strength, which is simply a brew’s concentration of coffee.
More formally, STRENGTH is the ratio of the number of coffee compounds to water molecules in the finished brew. It may seem a little obvious to us now, but in the fifties Dr. Lockhart had to come up with and then document the idea that people have preferences for the strength of their coffee. It turned out that the average person preferred their drip coffee drinks to be about 98.8% water.
More specifically, average Americans prefer about 1.15-1.35% of each brewed cup to be comprised of the compounds from the beans themselves. So a perfectly brewed coffee with an IDEAL BALANCE will fall within the center of the SCAA’s Brew Control Chart shown above, with approximately 20% of a bean’s dry matter diluted to about 1.25% of a brewed cup’s contents. Accomplishing both of these tasks simultaneously takes a combination of knowledge, skill and experience.
For more information about brewing fundamentals or to sign up for our training programs, contact a Customer Care Associate at 800 835 5943.