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1.
This is a mismatch between the profile curve and the preheat power setting. In the case of the default profile this is intended. The designer has chosen to ensure that the roast never goes below the line by aiming high and relying on the control system to get the roast back on the profile before colour change. If you want to tune the profile so that the roast follows better for a particular type of bean, then adjust the preheat power setting down and save your customised profile. With a little trial and error you should get the one particular bean type to follow nearly perfectly.
2.
This is the onset of exothermic reactions that start before first crack and continue after it. The Kaffelogic control system is designed not to react sharply to this, so it takes almost to first crack to get back on the line. What is happening is that the beans are supplying a little bit of heat of their own from chemical reactions. It's not terribly desirable for the control system to react hard because by the time it reacts it will need to drop the RoR in order to get back on track. It doesn't do this, but what if you could tell the control system, in advance, to expect and anticipate? You can with a zone boost. Details are in the Roaster's Companion available from our support page. The exact amount of boost needed, as well as start and finish times, will vary from one bean type to another. You will want to finish any negative boost prior to the onset of first crack. You might find a setting that acts as a good general setting for the beans you tend to roast.
3.
This is the onset of exothermic reactions that start before second crack. This can be anticipated and corrected for with another zone boost.
Another member has asked about modifying the PID control parameters, specifically about adding some integral gain. While you are free to experiment with this, we have found that any integral gain de-stabilises the control system. The Kaffelogic PID system has a unique algorithm for calculating the error that drives its set point and the maths behind it is very different from other PID roasting control systems.
