Home coffee roasting is as fun and easy (or as exacting and technical), as you want to make it. You can roast in your oven, use a skillet, re-purpose a popcorn popper or buy a fancy coffee roasting appliance. Whatever method you use, you will be on your way to drinking much better coffee.
How to roast coffee bean at home!
The basic process is simple: use heat to turn green unroasted coffee into brown roasted coffee. Roasting times vary, depending on the method and batch size but you can expect the process to last about 10 minutes for smaller batches and about 16 minutes for larger batches.
Method using a popcorn popper
Roasting your beans on a stove top is best done in an old popcorn popper. The best are crank-style poppers that can generally be found at second hand kitchen supply stores or online. Roasting your beans on the stove top will result in deeper notes and more body but will reduce the aroma and bright notes of the beans.
Place the empty popper onto the stove top. Bring it to a medium heat so that the temperature of the popper is about 450 °F (232 °C). If possible, use a deep fryer or candy thermometer to check the temperature of the popper.
If you don’t have a popcorn popper and don’t want to buy one, you can use a large skillet or pan. Make sure that it is very clean or else your beans might pick up the flavor of whatever was cooked before them.
Add the coffee beans. You should only roast 8 ounces of coffee beans at a time. Close the lid of the popper and begin turning the crank handle. You will need to continue stirring constantly so that your beans are roasted evenly.
If you are using a pan or skillet you will need to stir constantly as well--there is much more of a chance for the beans to burn in a skillet or pan.
Listen for the crackling noise. After about four minutes (though it can take up to seven minutes) you should begin to hear a crackling sound--this means that the beans are beginning to roast. At the same time, the beans will start producing coffee-smelling smoke that can be really potent. Turn on your oven hood fan and open a window to let the smoke out. Note the time when the beans start to crackle.
Check the beans’ color frequently. After the crackling starts, wait one minute and then begin to check the color of the beans. When the beans have reached the color you want, pour them out into a metal colander and continue to stir them until the beans cool.