Have you had coffee leave you with a sour stomach and an unpleasant, jittery feeling? Or one that tastes burnt and bitter? We usually attribute these characteristics to a particular style of coffee roast or brand of coffee. Maybe it’s neither. In many cases it’s the roasting equipment causing the undesirable flavors. You might stumble onto this realization by having a cup of extraordinary coffee (like when we first roasted at home) and discover air roasted coffee.
Using hot air to roast, you taste the coffee-not the roaster. In a traditional (and honestly, much cooler looking) drum roaster, the green beans are heated through contact with the hot, rotating cast iron drum along with heated air flowing through. Sort of like a really hot, really expensive clothes dryer. One of the by-products of roasting is chaff, which is the outermost 'skin' of the bean. In an air roaster, all the chaff is whisked up and away by the exhaust fans as soon as it separates from the bean. In a drum roaster, some of the chaff ignites, producing smoke that changes the flavor of the coffee. Think about cooking blackened catfish in a cast-iron pan with the vent fan off...get the idea?
Our roasting system levitates the beans on a fluidized bed of hot air, keeping the beans moving and not scorching on hot surfaces. The sole use of hot air greatly increases the rate of heat transference to the beans, creating a cleaner, more aromatic roast free of smoky, bitter tasting tars. Our roaster creates no combustion by-products and no greenhouse gases, except those created when generating the electricity we use.
Since you've stuck with me this far, I'll leave you with a little story. To frame this properly, you need to know that there's a bias in the coffee roasting community toward those super-cool looking monster drum roasters you sometimes see in upscale coffee shops. Admittedly, there's something romantic about those giant, clanking, gas-sucking behemoths, and they're wonderful for posing in front of for hipster photos.
When Bama Bear was fresh back from Tuscaloosa, Papa Bear entered him into a roasting competition which, unbeknownst to the boy, included some big names in the Bay Area coffee scene. Several pounds of beans, all from the same 'mystery bag', were doled out to the competitors to roast and and compete with. At the end of several rounds of blind tasting, guess whose roast came out on top? Hint-if it wasn't Bama Bear's, I wouldn't be telling the story... It opened a few eyes and changed some folks' views of air roasting and the quality of the product it produces.