I've been thinking about this RoR stuff per Rao.
Previously, I"d set target temperatures for various nodes along the way and try to hit those. Reviewing the RoR (or Delta T, as RoastMaster calls them) curves, I find that my roasts generally don't accurately follow declining RoR, but have dips or reversals of the kind that Rao warns against.
Thus it occurrdd to me that it would be useful to set up idealized curves to act as control or guide curves when roasting specific bean types.
Let's imagine, for example, an 13- minute roast. If we arbitrarily project a turnaround at two minutes with a trough reading of, oh, say, 105°C and a projected finish temp of 205°F-- again wholly arbitrary choice of temp-- then we've got 10 intervals and an overall Delta T of 100°.
So, you math experts, here's my question. What's the formula or method to achieve a steadily declining RoR (decreasing individual intervals between 1-minute readings or nodes) and have them add to 100°. My intuition is that such a formula exists.
I was able to plot out a curve last evening by trial and error to within 1° of 100°, but would appreciate being instructed if there is a repeatable way to do this mathematically.
Thanks for any enlightenment anyone's able to provide.
Cheers,
james
