I'm glad to hear you enjoyed your training with Willem Boot. He has published a lot of interesting articles on roasting and seems very knowledgeable on coffee. I did my training with Mane Alves at Coffee Lab in Vermont. We roasted both on a small Probat 5kg and a Diedrich IR-3. However, I might try to attend to the "advanced" training with Diedrich sometime to better exploit our Diedrich IR-12.
When dropping at 385f, what are your batch size? I rarely drop below 415 when roasting 9+ kg. Then again, we might have a totally different weather :) Also, at which temperature do you usually bottom out? I usually get my turning point at around 165f @ 1:30.
I opted for the manual roasters so I'm working with "WC. I attended some of Willem Boot's courses in Mill Valley CA. Although he does not yet roast on a Diedrich for training purposes, his courses were a superb introduction to the art of roasting.
It's great to find some roasters using the Diedrich machines on this forum!
Best of luck,
Another issue that may effect your times and development is the altitude you roast at. I am around 7000ft., which effects batch size, airflow and finish times. Without as much air for the roaster, most of my roast finish between 16-17 minutes.
Yet on the cupping table, a nice African still comes across with tons of nice acidity and non of the issues you would expect with longer roast times. I guess it really all boils down to what you like, and how you personally choose to get there.
Under the profile development section they suggest roasting at least 10 batches of the same coffee to zone in on the right profile. Have you tried this technique or do you have an alternate solution? I think I would be drowning in coffee if I used this technique on every coffee.
I roast on a Diedrich Hr-1 roaster, this is the electric type. In my user manual I dont have a section called Profile Development. I would be grateful if you could say something about what Diedrich writes about this topic in your manual?
Try contacting Diedrich for a reprint on this section. If they will not email you a copy, I will attempt to get you the information. I have an IR12 and have never used the "profile development" as described above. I migrated from a atmospheric roaster so I had many profiles which I adapted to the IR12. Although Diedrich's technique looks like it would help narrow your choices, I also felt I would be producing too much coffee. My method while not very scientific is simple: I roast and cup. If I feel like tweaking, I will change it up looking for a better outcome. There are some excellent guidelines in this thread that should provide basic information. Hope this helps.
I have been in contact with Diedrich, and they simply cant find this section. Could you be specific about where this section is? Is it in the manual of the Ir-12, and wich year was this roaster produced. The guy that I have been in contact with at Diedrich would like to know more details about this section, that would give him a clue where to look:-)
Stephan Diedrich's approach to developing a roast profile can be found in the 'Roasting Workshop Summary' booklet which is handed out to participants of the roasting workshops held at Diedrich's facility in Sandpoint. It's a big undertaking to follow the procedure as outlined and it does require a lot of time (it says about 10hrs of roasting and cupping in the manual) and coffee, however its probably the most thorough description you will find of how to tweak your roast so that you bring out the maximum flavor potential possible in the beans you stock. Stephan is absolutely passionate about coffee and this approach reflects his philosophy that good coffee deserves this type of treatment.
You can find an outline of Diedrich's approach to developing a roast profile in the SCAA Library in a transcript from a presentation given at the 14th Annual SCAA Conference held in Anaheim in 2002. The presentation is entitled "How to Obtain Excellence with Drum Roasters" Use the search function in the SCAA library found on this link.
Hope this is some help
And there it was. Thank you very much. I even listened to the whole thing with Stephan Diedrich, Torrey Lee & Carl Staub. Would recommend that to everyone.