The Roasting Process, Levels of Roasts, and the Agtron Scale

What is the roasting process?
The process of beans being heated up to release flavor. 

Coffee beans are actually seeds, and they need to go through the roasting process to produce the keen coffee flavor that coffee lovers are accustomed to. When the beans are raw, they’re actually green. The roasting process involves physical heat treatment to draw out the essence of the bean. 

You may have seen small cracks on coffee beans before. Those are an essential part of the roasting process that show the roaster what stage of roasting the beans are in. The first crack is very important - it means the coffee flavor is being unlocked and is almost ready. 

Then, there’s the second crack. Another essential element of coffee roasting, the second crack will appear after more heat has been applied. 

So, how are these cracks made? The heat causes the coffee to expand, allowing moisture to evaporate. That moisture turns into steam, then pressure, which pushes into the bean as it tries to escape, causing cracks to form. The development of the roast depends on the stage of cracks the bean progressed to before it was pulled from the roaster.

Levels of Roast
Light roasts are more acidic and dark roasts are more bitter. 

Light 
Smooth, Fresh, Acidic 

Light roasts have a light brown color and only have one crack. They usually finish the roasting process just after the first crack. They’re acidic and sometimes have somewhat of a fruity smell to them.

Medium-Light
Sweet, Balanced, Aromatic

A medium-light roast is exposed to heat just slightly longer than a light roast, giving it more time to produce aromas and a fuller flavor.

To experience a medium-light roast, we suggest Costa Rica, Ethiopia and Firepower.

Medium
Bright, Balanced, Smooth

Medium roasts are usually finished moments before the second crack. Their longer roasting time gives them a flavor that is more rich and complex than lighter roasts. They have a stronger flavor than light roasts, but aren’t as bitter as dark roasts. Medium roast is what you’ll typically find in a breakfast blend. 

Some of our favorite medium roasts are Le Réveil, Colombia and Peru. 

Medium-Dark
Rich, Bittersweet, Full-Bodied

Medium-dark roasts have a full, rich flavor that maintain the balanced quality that medium roasts have. They’re pulled from heat briefly after the second crack. They have a full flavor and sometimes leave a bittersweet aftertaste.

We love our Honduras medium-dark roast.

Dark
Bitter, Deep Flavors, Low Acidity

Dark roasts continue to roast for some time after the second crack. The longer roasting process produces deeper flavors and reduces the acidity. Dark roasts are most commonly used for espresso brewing.

Nothing beats our Barrel of Monkeys dark roast.

What is the Agtron Scale?
A scale used to classify roast level.

The Agtron Scale is a scientific measurement that is used to classify roasts by color. It measures the light reflected off roasted coffee, on a scale from 25 to 95. It was created so there was an objective measurement of roast level. It’s a popular method of measuring roast level because it’s repeatable and fairly easy to use. Coffee companies use this scale to determine which of their coffees are light, medium, and dark roasts so buyers can count on having the same roasting level each time they buy a bag. You may see the Agtron Scale mentioned on coffee websites when referring to coffee roast level.

What roast should I pick?

The roast level you choose depends on your personal preference. While some roasts might pair better with certain brewing methods and added flavors, coffee is a treat that should be enjoyed your way. If you don’t know which roast you prefer, hang in there. We recommend trying coffee from each roasting level until you find the one you like best!