Yes another coffee roasting post.
I’ve been having another go at roasting my own beans, and have now moved onto a new variety called “Indian Tiger Mountain”.
I’ve also worked out how to make my little home coffee roasting machine work properly. So this last roast turned out really well. I hit the first crack at around 6 minutes, and the second crack at about 9-10 minutes. I’d never heard the cracks so clearly before, as my machine gets pretty noisey in full flight. For non coffee roasting type people (possibly everyone), coffee beans roast in a similar way to popcorn. Basically they have lot of gases and oils inside the green bean, which when heated up cause the bean to pop (crack). A roasted bean will crack twice during the roast cycle, and when it cracks for the second time you’re pretty close to being done (for a dark espresso roast). If you go much past second crack you get a whole lot of charcoal and a nasty mess in your laundry (or preferred roasting spot).
My problem before was that i wasn’t getting enough heat into my system, and the roast was taking a long long time (around 20 minutes plus) and the beans weren’t cracking like they should. So i made a little modification to my machine, by sealing half of the air vent with aluminium foil to cycle the heat back into the machine. I also added more beans so that it spins slower… in theory making sure more heat hits the beans on each cycle… This proved pretty successful, so unless i was just completely lucky i seem to have worked it out.
The resulting espresso was great. Thick dark crema laden cups of espresso that was smooth and a little fruity on a the palate. Without the harsh bitter aftertaste a lot of blends/single origins seem to create. I’ll definitely be roasting some more soon.