Unlike coffee, which roasts anywhere from 400-460F, cocoa beans need more gentle treatment. In that there are no hard or fast coffee roasting rules, the same holds true for cocoa. In general though, they can be roasted from 5-35 minutes anywhere from about 250-325 F. To do this, there are basically five options:
- Oven roasting
- Air roasting
- Drum roasting with a gas grill
- Coffee roaster
- Hot air gun, believe it or not
With all of the methods, the basic technique is the same. Subject the cocoa beans to a high temperature initially, slowly reduce the temperature and stop the roast when the beans are “cracking”, but before they start to burn.
The initial high heat lets the beans gain some thermal momentum and allows for a good separation of the husk and nibs as the beans expand. You lower the ambient temperature so as not to burn the outside of the bean, but let the interior continue to roast. Finally, the cocoa beans will start to pop and crack as water vapor is explosively released. This happens when the cocoa bean temperature is around 300 F. This is your sign you are just about done roasting. Experience and smell (you don’t want any burned smell) are the key indicators when the beans are roasted. Once the cocoa beans are roasted and cooled, try separating the husk from one. If it comes off easily, you did well and the beans are fully roasted. Likewise, taste some. They should have a nice cocoa flavor, with no raw or burned flavors.
Generally I like to have a roast take 15-30 minutes, regardless of method. Under that amount of time and the beans seem to retain a raw unfinished flavor. Over that and they start to taste baked and sort of flat.
