I roast coffee for a living for a micro-roaster in New England and am able to roast on both a Probat and a Diedrich in our facility. My question is relative to airflow and equipment preference out there: The Diedrich design only allows for an 80% flow of air through the roasting drum during a roast while the Probat allows
for 100%. Every time, the "brightness" or acidity of the cup is far better in the Probat coffee than the Diedrich. Can that 20% difference really affect it that much or is there something else going on there? Also, does anyone know if Probat makes a roaster that can roast/cool at the same time like the Diedrich? I'm curious to know if anyone has seen that or drank coffee from a new line of Probat machines. Thanks so much and happy roasting! ~Patrick

do you know exactly how long is your roasting time in each roaster.

I roast coffee to a medium roast profile, so the range of time, depending on various factors (type of coffee, ambient temp etc.) is 13-14 minutes.

i currently roast on diedrich with the handy computer profiler. I roast manually and achieve good results and tend to have 16 minute roasts on average. i get first pop at 380 degrees and 11 minutes. i change air flow then and continue with roaster air flow till 420 degrees or 13-14 minutes when gas gets shut off and air is back to 50/50. the beans do the rest till target temperature 445 for full city.
my only issue is with chaff leaking out of the drum to the burner area. not cool but i dont know if i should try to dismantle my roaster to tighten up the tolerance..

no gas for the last 2-3 min?
I've got one word for you: baked.

Java roaster 99,
Sure Probat makes all kinds of stuff that cools and roasts simultaneously. Caleb up at Metropolis in Chicago doesn't wait to cool off one batch before starting up the next. You just need a dedicated blower for the cooling tray.