Colombia Finca Buenavista -Carlos Imbachi Microlot

Boy, did I forget how hard stainless steel is to machine with home tools. Over the weekend I set out to install a thermometer probe into my Hottop, following the basic method outlined here. Sounds easy, right? Well, let's just say that much cursing ensued as I tried to drill through things with my electric drill. Anyway, its in there, giving me access to the actual bean mass temperature instead of just the Hottop's sensor which is bolted to the back wall. And a good thing, too! See:

This was a roast of a Columbian bean that I had ruined (and never blogged about, of course) with my Gene Cafe when it was having troubles. The blue line is from the Hottop readout and the pink from my new thermoprobe. Obviously, one should pay attention to the pink line, which is a fast acting K-type thermocouple buried in the rotating beans. You'll notice the temperature drop when you add the beans which is not sensed by the stock thermocouple, and the eventual crossover of the curves.

I highlighed the times where I played with the heater power to slow things down, and I also boxed out the area where first crack started and ended from about 10:45 to 13:30. What I was attempting to do was slow down the rate of heat transfer going into first crack in order to improve flavor development and have enough time after the end of first and before the onset of second crack. You can see that I stalled things out a bit where the pink curve flattens around 11 minutes in, and eventually it ramps up again later until I dropped the beans into the cooling tray. I need to play with the heat and fan settings more to have a slow but steady temperature increase instead of this stalling behavior. This roaster is like driving a Ferrari compared with the very slow reacting Gene Cafe. Still, you clearly need to anticipate things by a minute or so given the electric heating on the Hottop. Lots of room for improvement, that's for sure.

Anyway, the coffee was a nice City+ roast and was actually a decent cup. There were very intense fruity notes both in the aroma and taste. I called it tamarind in my notes, but I see that Tom from Sweetmarias called it guava. Your choice. The acidity was nicely controlled, and the cup was quite refreshing. As it cooled, there was a bit of a flavor change that is hard to describe, but I attribute it to stalling out the roast a bit and having things drag on too long. Let's call it "flat". Most people wouldn't pick up on it, but after roasting a lot of coffee I am starting to be able to tell what went wrong.

My next few efforts will be to speed things up a tad, and keep playing with the heat settings.