Pyrolysis: it's not a state of immobility! The process of roasting coffee is often referred to as pyrolysis. How much do you really need to know about this process? Well, unless you're a chemist or whole-hearted coffee nerd, probably not much. The really great thing about the term is that by bandying it about in conjunction with other words like profiling and full city and flavor nuances, we roasters sound really really smart and professional and chock-full of expertise and clearly worthy of your trust, and hopefully, your money. Interestingly, pyrolysis is defined in the Merriam-Webster dictionary as a "chemical change brought about by the action of heat"; this means--gasp--that pyrolysis is not a term strictly within the domain of roasters. But like I said, I feel pretty smart when I use it. When green coffee beans are roasted, this is what happens: 1. the beans turn from green to yellow to light brown to darker brown, depending upon the degree of roast desired. 2. The beans lose water and, therefore, weight. 3. The beans get bigger. 4. Flavor oils move gradually to the surface. That's about it in a nutshell, although the chemical process the beans go through is HIGHLY COMPLICATED AND NOT ENTIRELY UNDERSTOOD, ESPECIALLY BY THE LAYPERSON, WHO SHOULD ONLY TRUST ROASTERS WITH WILD HAIR WHO'VE BEEN ROASTING FOR TWENTY-SIX YEARS. The trick for the roaster is to quench the roast at exactly the right point, which means balancing the flavor nuances (doesn't that sound great?) with the roastiness. Too far, and all you taste is the degree of roast. Not far enough, and the coffee tastes green, overly nutty--almost raw in my mind. Check out this link to Sweet Maria's for a great overview: An Updated Pictorial Guide To the Roast Process. And by the way, I'll sell you green beans also, at a twenty-five percent discount. For those of you who insist on drinking your coffee lighter than the Full City option I've included on our order page, I'd be happy to custom roast a mininum of three pounds per variety however you'd like. Just let me know via email!