Hi, I work for Pumphreys roaster in the Uk.
Just to explain the roaster:
As jason_casale said the flames are totaly contained in the drum.
The basic theory is that the beans are tumbled over a naked gas flame like a washing machine. You have to know you coffee very well and be able to read its deveopment through colour changes, sounds, smells and 'hunches'. It is very basic and I'm sure a lot of people would learn a lot more abou their coffees if they roasted like this for a week or a month. My uncle is the roaster featured in the video and has over 30 years experience. I don't think I've met anyone yet who can roast as well as him.
As for the output: it produces a very good looking bean with a slight case hardening. Handsome to look at as even cinnomon roasts have a very slight shine. Not from any oil which has begun to sweat out but from the hardened case. The best analogy: Roasting a chicken or microwaving a chicken. The roast chicken looks better and when cooked correctly tastes fantastic, Microwaved chicken is bland and tastless. Keep all the flavour in the bean as much as possible.
I'm using some of our coffee to enter the UK barista championship so I shall tell you how it matches up against the other types of roast.
Stuart Lee
http://www.mentness.wordpress.com
