Coffee Roasting

Coffee roasting is the art and science of roasting the green coffees at approximately 400 degrees. Although sounding simple, roasting and blending are two of the most important aspects of creating a great gourmet coffee.

The roasting process caramelizes the sugars and carbohydrates in the beans creating an oil-like substance which gives the coffee its flavor and aroma. The longer the coffee is roasted, the darker and more oily its appearance becomes.

Roasting Equipment

The two most common types of coffee roasting equipment are the drum type machines and the hot air roasters.

The drum machines roast the coffee as it is tumbled in a rotating drum.

The hot air machines, also known as fluid bed roasters, roasts the coffee as it tumbles on a current of hot air.

Both machines keep the coffee moving to maintain a consistent and even roast.

Green (unroasted) Coffee

Not only does it smell great, but buying green (unroasted coffee) and roasting it yourself could save you alot of green, if you know what I mean! A good green coffee to get started with is Yemen Mocha Green Beans 5 Lb Bag . They have plenty more to try though. Experiment and impress your friends with your own, house coffee!

The Roasting Process

The First 9 Minutes:

Once the coffee roasting begins, at just 3 minutes, the beans emanate a grassy fragrance. At about 5 minutes, the beans begin to swell and change colors from green to yellow and then gold. It is now that the smell changes to that of toasted wheat. At about 9 minutes, the coffee begins to wrinkle and look ruined.

The First Pop:

Around 10 minutes, gasses build up in the beans causing them to swell to about double their original size and then rupture. This rupture releases the gas and can be heard in the roaster kind of like popcorn.

The swelling smoothes out the surface of the bean and then it begins to even out in color to a very light brown. This is the lightest roast and is referred to as cinnamon roast.

The Second Pop:

After about 11 minutes, the color changes to a darker brown known as full city. At around 12 minutes the color and aroma of the coffee begin to change very rapidly. Just as in the first pop, the gasses build up and burst creating a second pop.

The Dark Roasts:

At around 15 minutes the coffee beans now look very dark. A little bit more and we finally come to the darkest roast, the French roast. It is important to note that this has nothing to do with where the beans come from, just how much the beans are roasted. In Europe, this is sometimes known as the Italian or Espresso roast.

At whatever stage the roaster decides to stop roasting, the beans are poured out onto a cooling vat which stirs the beans to quickly cool them in order to stop the cooking.

After the beans are roasted, they begin to give off vapors for about a day or two. When this is complete the coffee will be at its optimal flavor. Quality roasters will package the freshly roasted coffee in special bags that are air tight and have one-way valves to let these vapors escape.

It is important to note that the freshness of coffee has to do with when it was roasted not when it was harvested. After roasted coffee has been exposed to air, the flavor will begin to deteriorate extremely fast. In fact, a huge portion of the flavor is lost in just 7 to 10 days!