another_jim wrote:Hi Martin, I just finished building a dual PID box mated to a P1 for a friend. About $250, and a lot more work than I care to do. I'll post the instructions at some point, so that people so inclined can do it themselves. That's about as cheap as it can get right now. As soon as a usuable PRC low cost PID controller with ramp/soak hits the market, it'll be a good deal less.
The box profiles the hot air supply on one PID based on profiles used in industrial roasters and cuts the roast at the bean temp set on the other PID. It's about as auto as it gets, since the ramped supply air profile is overload safe, maintains stably rising rost temepratures, and doesn't require manual airflw manipulations.
Sometimes we hear of a high-level, but sub-superstar athelete described as "he plays within himself." That's the sort of coffee roaster I am. Also, I've posted previously, somewhere, about anchoring my coffee endeavors in a principle of parsimony. So when I consider switching from HG/DB, I have to balance the new data and control I would get, with what I might actually use.
I suspect that roasters and methods that purport to add lots of useful data, actually add very little to HG/DB. For example, after weeks of monitoring temps of the HG/DB bean bed, I realized that temp was just an interesting data point that I could use to "describe" roasting decisions I was making that were based mostly on sensory cues. Over a series of highly replicable roasts (same blend, crop, varietys, etc) I might be able to decide within a few degrees an optimal degree of roast, but actual conditions make this unlikely; especially when considering my capable-but-not-brilliant cupping skills. Over time, the repetitions add up to increasingly informed intuition. To describe this process, as some do, as "Zen" roasting misses the point (unless you want to describe my bubbie as having made Zen strudel dough).
Now, of course, this does not apply to nano-roasting; in which case (and with great respect) the endeavor is not about getting some great beans roasted for tomorrow's breakfast. Finally, if a robust and nicely packaged dual PID box with mate becomes available, I'd love to own one. I also own "the ultimate driving machine" even though I'm not the ultimate driver.
Martin