Here is another great example of how useful a toaster oven can be. Be forewarned though, using your toaster oven to roast coffee will leave a distinct aroma that can be transferred to other foods cooked in the toaster oven. For this reason I keep an extra toaster oven in the garage that I mostly only use for roasting coffee. I have however, on occaision, used it to cook items that benefit from that aroma. Chocolate cake and roast beef are a few examples that come to mind.
A few years ago I was reading a cookbook that is a little over 100 years old. It plainly stated that "tea comes to use ready to brew; coffee must first be roasted." I was quite surprised to learn that coffee was regularly roasted in the home without any special equipment so recently. With all the expensive, technologically advanced home coffee roasters available today, it seems we have forgotten how easy coffee roasting can and should be.
Not long after reading that cookbook I ordered my first batch of un-roasted, green coffee beans. The resulting coffee was better than any I've ever tried. I haven't bought pre-roasted coffee since. Not only does roasting my own coffee result in better tasting coffee, it is also cheaper. I enjoy freshly roasted organic coffee for less than cheap conventional pre-roasted coffees.
There was a bit of trial and error that followed, but I can honestly say that even my worst batch ended up better than any coffee I had tried before roasting my own. I have roasted coffee on the stove top, in a popcorn maker and in the oven. I have used my gas grill and the side burner on it. The biggest problem with roasting coffee is the large amount of heat and smoke produced during the process.
About a year ago, I found the perfect solution. I now have a toaster oven that I keep in the garage just to roast coffee. It keeps the heat and smoke out of my house. As an added bonus, my garage now smells like an upscale coffee shop.
Many die-hard coffee roasting enthusiasts will tell you that baking coffee in an oven is not the way to go because it will result in an unevenly roasted batch of coffee. To them I say: You are both right and wrong. Yes, the roast will be uneven. But this only adds to the complexity of harmonious flavors in the final cup of coffee. You will end up with the strong, rich flavors of a dark roast accompanied by the soft, fruity flavors found only in a light roast. I have tried methods that roast the coffee more evenly and the resulting cup of coffee is just not as good.
So what do you need to turn your toaster oven into a coffee roaster? Just a shallow baking pan, metal colander, oven mitts and green coffee beans (those can be found online and delivered straight to your door.)
Crank up your toaster oven to its highest temperature setting. The higher your toaster oven goes, the better it will work for this task. Spread the green coffee beans out on the baking pan in a thin layer. Place into the warmed toaster oven. How long the process takes depends on many factors. The amount of moisture present in your beans, the ambient temperature of the room and how hot your toaster oven gets all play a role. I've had batches that are done in as little as 10 minutes and some that take as long as 30 minutes. All you can do is listen and wait.
So what are you listening for? The coffee will "crack" and you will hear popping and cracking sounds. After the first crack, you have a very light roast. If the coffee is left in the oven it will get to the second crack stage, which means a very dark roast. Everyone has different tastes, but I prefer mine somewhere between. I normally remove my beans as soon as I hear the start of second crack, or sooner.
Be very careful removing the beans; they will be extremely hot. Transfer them immediately to the metal colander and swish them around for several minutes. This does two things. First, it helps the beans to cool, thereby stopping the roasting process. It also helps separate the beans from the chaff (a papery layer on the outside of the beans.) Do this outside, and the chaff will simply blow away. Don't worry if all the chaff isn't removed, it's perfectly fine to brew coffee with some chaff attached.
Transfer the beans to a glass jar, but don't cover for 4 hours. Then tightly cover the coffee until you are ready to use it. The roasted coffee will remain exceptionally fresh for about a week, and will still be fresher than what you buy at a store for months to come.