Introduction to Roasting Coffee

I recently attended a class at Mr. Green Beans in Portland, Oregon.  I had signed up on my first visit there, and was anxious for the refresher, an Introduction to Home Roasting.Read: Profile Mr. Green BeansI've been dabbling in roasting my own coffee at home for a few years now.  The coffee bean is the seed of the coffee cherry grown in hot, high-altitude parts of the world, and is green and smaller in size before it's roasted.  There are many reasons to roast your own coffee, other than it's way cool to do it.  Coffee is at its freshest right after it's been roasted, so when you roast it yourself, you're guaranteed a very fresh and flavorful cup of coffee. [ad#Google Adsense - use me]The class costs $20.  For the time and expertise of owner Trevin Miller for almost two hours, and a bag of unroasted coffee to take home, that's pittance.  The other elements of a home roasting class:- Five samples of coffee throughout its roasting stages, from green to dark, so that you can see how it changes throughout the process.- A small bowl of chaff, the "skin" that flakes off of coffee as you roast it.  This is a natural by-product of roasting, so important to understand.- A sealed jar of the same coffee that Trevin roasts throughout the class, so you can appreciate the final product.- Takehome instructions so you remember what you learned.- A copy of Roast Magazine, the industry's leading trade journal.Eleven of us showed up for a class that seats twelve maximum, a great turnout!  Trevin walked us through the various methods of home roasting, from the simple frying pan still used traditionally in Ethiopia to roast coffee.  To the popcorn popper, whose core technology is the same as those used in more advanced home roasting machines - the science after all is heat and movement of the beans, the same way we pop corn.I think it's always worth going back to school.  Take advantage of any coffee roaster or home roasting provider in your area that provides such instruction, so you can see it for yourself.Since I never formally learned home roasting  until now, here were some great takeaways from the class:- There are origin characteristics to the coffee bean depending on where and how it was grown.  Then there are roast characteristics that impact flavor from the roasting process itself.  The darker the coffee, the less of its origin characteristics you are enjoying.- After you roast coffee, let it breathe for 1-4 hours.  There is outgassing of CO2 taking place before the beans start to expire due to exposure to oxygen.  If you seal them at this stage, you're sealing them with the CO2 that hasn't properly outgassed yet.- You have to cool your beans after they roast.  Otherwise, the heat inside the bean will continue to roast it even after you've shut down the process.  I knew this, but was throwing the beans into the freezer to cool them down.  It's a dramatic temperature change, and coffee will absorb the odors of what's in the freezer.  All I need is a simple metal collander in which to shake the beans until they've cooled.