How is Coffee Roasted?

Previously, we've talked about how coffee is grown, harvested, and processed. We've reached the final step before we send delicious coffee to your door: roasting.

History of Roasting

Coffee roasting is the process of cooking green coffee beans, which teases out their natural flavor. The first roasting emerged in the Middle East in the 1400s. At first, the process was simple: heating beans in pans over a fire.

Around 1650, drum roasters, devices with a rotating drum to heat coffee beans evenly, appeared. In the 1800s small-scale roasters were made available, and in 1864 Jabez Burns invented the first commercial self-emptying roaster. Modern coffee roasters vary from small-scale machines to ones that can roast thousands of pounds of coffee per hour.

Steps to Roasting

First, green coffee beans are placed in a roaster, which tumbles the beans in hot air like a clothes dryer. The temperature is slowly increased to 460-530 degrees Fahrenheit. The goal is to end up with each bean evenly toasted to its core.

While the green coffee beans roast, they release their moisture as steam. As they dry out, the beans turn yellow and then brown, producing a toasty aroma. The coffee beans shed their silverskins and enlarge.

When the temperature reaches the optimal point, the coffee’s remaining moisture is released; the beans fracture with a loud popping sound (the “First Crack”) and expand further. After this point, the coffee’s sugars caramelize and release oils, and the beans darken rapidly. The roaster can stop roasting sometime shortly after the First Crack or continue on to a second, more metallic popping noise (the “Second Crack”) to get a darker roast. The coffee must be removed not long after this Second Crack to avoid complete caramelization of the sugars and an overly bitter or smoky coffee.

Coffee beans after roasting

The most difficult part of roasting is determining when to stop. Roastmasters take note of the color and odor, sometimes using special instruments, to do so. At the determined time, the beans must be quickly cooled to prevent additional cooking while the roaster cools. Many roastmasters do this by pouring the beans from the roaster into a silo that rotates the beans while passing air over them. However, some simply spray the beans with water or flood the roaster with cool air. Then, for the 24 hours following roasting, the beans must be degassed, or left to sit while the bean releases carbon dioxide. Beans should not be ground until the degassing phase is complete.

Different Types of Roasts

Generally, light roasts are more acidic and sharper than dark roasts. The flavor palette is often baked or grain-like (similar to toasted bread) and can be somewhat sour. Beans will be light brown and dry, and the coffee will have minimal body. Different light roasts include the Cinnamon Roast, which is removed at the beginning of the First Crack and has hints of grassiness, the New England (a little darker), Half City, and Light.

Cadena's Colombian coffee is a good example of a light-medium roast.

Medium roasts produce medium light brown beans. This degree of roasting includes American, City, Medium, Brown, and Breakfast roasts. The American Roast preserves the original character of the bean but is less acidic than a light roast; it’s frequently used for professional coffee tasting. The City Roast is slightly darker than the American and common in the western U.S. It is bright and sweet, with fruity tastes and a light body.

Cadena's Papua New Guinea and Mocha Java coffees are good examples of medium roasts.

Coffee cups

One step more roasted is medium-dark, which, as the name suggests, has medium dark brown beans. Medium-dark roasts include Full City, Light French, and Vienna. Full City coffee is removed at the beginning of the Second Crack, when the roast flavor begins to dominate. It has a taste balanced among bittersweet, chocolate or caramel, and ripe-fruit tones as well as a medium body. Occasional oily drops are present on the beans’ surface. Light French and Vienna Roasts are slightly more roasted. The Vienna has a light oil coating and is more bittersweet, with caramel flavor and low acidity.  

Cadena Coffee offers Honduran and Nicaraguan beans roasted in the Vienna style.

Dark roasts have lower acidity, fuller flavor, and less caffeine than lighter roasts; beans are very dark brown. Dark roasts are popular for espresso and after-dinner coffee. Other types of dark roasts include Continental, European, French, and New Orleans. The French Roast is removed at the end of the Second Crack. Shiny with oil, it has burned overtones and a thinner body.

Very dark roasts include Dark French, Italian, and Spanish Roasts. The beans are roasted until they’re almost black and nearly all the sugar is caramelized. The flavor is usually flat with hints of charcoal. The Spanish roast is the darkest.

Whatever your personal preference, pick up a bag of Cadena Coffee today to explore different roast options!