Coffee – Roasting, Not Boasting
Home wine makers will be happy to hear that roasting coffee beans is even easier – and the results are often as good as the pros.
A variety of roaster types are available, but even a frying pan or popcorn popper can be used. Be sure to start with ultra-clean equipment, though. Nothing spoils the taste of coffee like left over fish oils or butter.
Dark roasts contain a little less caffeine than lighter roasts, but they lack the acid taste of the latter. Be sure to start with quality beans, of course!
The beans will need to heat to between 460F (223C) and 530F (262C), so be prepared for some smoke. That’s easily taken care of with a small room fan or stove top exhaust. Beyond the smoke there will be an odor, so your first experiments should probably be done with the windows open and no one home.
Put the beans in the roaster and turn up the heat! (Take care to be ready to temporarily disable those over-sensitive home fire alarms.)
For some roasters, the thermometer is built-in, but you may want to have an extra for when it’s open, or for those frying pan experiments. Candy making thermometers work well for the purpose.
During the process those green beans will turn yellow, then brown. How brown depends on how dark you like your roast, which is always an individual choice.
As they begin to heat up, moisture – both oil and water – will put pressure on the bean surface and you may hear a loud crack when it bursts. Not to worry, this is normal. Stirring every 30 seconds or more, you’ll hear this after four to seven minutes of heating.
The sugars inside will begin to caramelize (turn brown and ‘burn’ slightly) as the roasting continues. Again the degree is a matter of taste. Check the color every 30 seconds or so.
Roast long enough and sometimes a second loud crack will occur. At this stage the beans will be quite dark and for some palates a little overdone. Beyond the second crack you’re really just burning the beans and boiling away the sugars. The results will be too harsh for most.
Pour into a metal colander to cool, then agitate. Since the roasting process produces chaff (a fine skin that detaches from the bean as they’re agitated), you’ll want some method for removing it. Mesh cooking screens are one option.
Try a few batches with varying degrees of time or darkening. Experiment to get the flavor you like. Keep in mind that the heat trapped in the bean will continue to cook it for a short while, so try stopping a little short of your desired end goal.
For the popcorn popper style roasting, be sure to get one that allows you to stir up the beans to keep them moving around and not sticking to the surfaces. For the stove top style, a cast iron skillet works great. Be prepared for lots of stirring and viewing. Roasting happens quickly!