I've just started roasting new samples of Oko Caribe, trying a total of 8 combinations described below. Hopefully some of you will have suggestions for things to try.
First, about the equipment: I use perforated cheats in a commercial convection oven with excellent air flow, a single layer of beans on each pan. Prior to this I had used a Gene Roaster, a Behmor and a home oven. The Gene Cafe and oven get similar results at equivalent temperatures, often 20% below the reading needed for a similar roast profile on a conventional oven.
On to the specifics: in previous experiments I found that some cocoas do better with a drying / pre-heat phase. I use 20 minutes at 65C, the lowest available setting for my oven. For each temperature I have two sheets, one that goes through the pre-heating phase and one that does not. This time beans were removed at 18 and 20 minutes.
For the roast tests I was joined by a friend with a great palate. We hand-shelled beans from each sample and mixed nibs (I'm thinking of using a mortal & pestle next time) to get a representative sample without getting too wired.
18m: floral notes with peanut, coffee, fudge and brownie
20m: more chocolate flavour, notes of espresso
18m: sticky shells, beans still hard. Peanut, strong acid, green banana
20m: brazil nuts (!?). fairly astringent but with a nice bourbon / malt, a slight smoke.
18m: nutty. spice notes: nutmeg, clove. some harsh acids. "warm"
20m: minty, pepper aftertaste, less acidic, not very astringent.
18m: pretzel (!?). Fruity acids, a favourite.
20m: coconut. astringent; spice and espresso.
The next tests will be "no pre-heating, 22 minutes @ 100C" and "10m pre-heat, 12m @ 118C".
Is there anything else you would try for roast profiles or to change my protocol? Thanks in advance.