crunchybean wrote:I have had very promising results on the "diedrich style", though to be honest I had no idea it was called that.

Looks like Almico is a bit of a Rao fan...

I do not have a dog in this race at all. I'm a fan of anything that gives me better coffee. I tried hard to refute Scott's sometimes sensational claims. They did not sit well with me. But when I honestly set out to rigorously test them, I confirmed every one. I will not bother with the "Forte is better than EK43". I had a Forte and sold it. I will never have an EK43 and likely never own a Decent espresso machine.

The OP question was about different roast profiles. But we've come to Rao. Again. I don't doubt it, but your testimony for Rao Commandments is no rues. I like Rao's theories and also saw that they fit well with others. But it's that conventionalism: "it did not sit well with me", here's a guy who spent lots of waking moments for some part of a decade thinking about roasting and then you say "boy, I sure don't like the way that sounds"...that barrier for me is frustrating. As a devout believer in science I must rigorously affirm my beliefs in the practice of it. If I were you I'd take the opportunity that you have with the Cormant and retry all the styles and beliefs. I will say buying a sample roaster to learn on was money well spent and fustration well earned. And I don't even have a bean probe...

Almico wrote:I believe you meant to say the BT curve plateaus. The BT RoR curve dips significantly as the roast slows down. It then needs to rise to complete the fast finish.

I have tried this several times with my fluid bed roaster and never found a rising RoR to help a roast, ever. I am willing to try it on my new drum roaster, but it will have to be a small batch, because recovering from the slow down, where heat momentum is shed from the drum, is hard to recover from without BTUs in reserve.

Nothing ventured...

Fixed. Yes thats what I meant, obviously the ROR line declines then rises again.

As for various roast styles, if one has a nimble roaster the world is your oyster. Generally im leaning towards an overall decline in ROR, some difficult coffees really leap up when allowed to slow down as they begin to yellow.
If started with enough energy as the ROR declines into yellow it can flatten out for a little while, as long as it starts to decline again around 175 all the way home ive found no major issues.

Even within a strict RAO style roast you can do lots of different things with gas application if roasting machine is nimble enough.

Almico wrote:I believe you meant to say the BT curve plateaus. The BT RoR curve dips significantly as the roast slows down. It then needs to rise to complete the fast finish.

I have tried this several times with my fluid bed roaster and never found a rising RoR to help a roast, ever. I am willing to try it on my new drum roaster, but it will have to be a small batch, because recovering from the slow down, where heat momentum is shed from the drum, is hard to recover from without BTUs in reserve.

Nothing ventured...

On the other hand I'm not sure what is referred to here.
For one, a plateau on BT would imply Zero (0) value on RoR.
Otherwise a plateau on RoR--speaking again about the man who is most often mentioned--goes against a recent assertion, that a plateau on RoR goes together with a flick and results in not as good coffee as would be attained without RoR plateau and the corresponding flick.
Returning to the BT plateau supposition with corresponding Zero RoR, this would be untenable because it implies a stall. Recovering from a stall does not produce good results, I think.
So likely the description argues (versus Rao) that a plateau on RoR can be worked in well. Often I have roasted with those, and also without, but please advance which was meant, and any further information. I'm interested.

Why does a plateau have to imply zero? Your implication is incorrect.

We were discussing the part of a roast where the beans are pale green and starting to transition into yellow.

Depending on how hot the roaster was charged and gas applied, it can be managed so that at this point the BT CURVE flattens out somewhat and forms a little plateau visible in the overall curve.

The speed of roast ROR at this time might drop to 9 to 12 degrees celsius depending on how long one wants to draw out yellow and the transition into browning.

The ROR line might stay flat and then increase slightly. In my experience if it is brought back to a slow decline from about 175 celsius all the way to drop then all is ok and there are no "RAO roast defects" or any other roast defects, just manipulation of flavour profile. No zero ROR or stalling required, just some imagination.

Everything he says about the end stages of the roast is true and when crashes and flicks are removed with a slow and steady decline the coffee tastes exceptionally good. Just blasting away on every coffee from the start of the roast is not, there is lots of crafting to be done prior to and as the coffee yellows and start of caramelise which RAO has said specifically he does not even look for or care about...

OldmatefromOZ wrote:Depending on how hot the roaster was charged and gas applied, it can be managed so that at this point the BT CURVE flattens out somewhat and forms a little plateau visible in the overall curve.

The speed of roast ROR at this time might drop to 9 to 12 degrees celsius depending on how long one wants to draw out yellow and the transition into browning. .

Thanks, seems a question of what one calls a plateau. An RoR of 9 to 12 degrees per minute' as the slope of the BT curve is not what I would call a plateau with respect to the BT curve. It slopes upward generously, whereas toward the end of the roast, when the RoR is possibly between 2 and 0 degrees C per minute then the BT curve is flat, or on a plateau. Of course if BT is held steady RoR is flat by definition. Anyway it's just words and abstractions; we do work with coffee.

I'm still not getting what "oldmate" is doing. 9-12c ROR is on the slow side and would most likely produce a longer total roast time. Sounds like the initial settings are adjusted not at all or slightly some time at the end of roasting? I've seen the "low and slow" profile advocated on a Mexican importers blog by his customers. It's another approach, just what the OP was asking for.

I've edited some off-topic comments that brush up against the site's Guidelines for productive online discussion. Participants are invited to review these before posting again. Thanks.

Pretty timely new book:

https://dailycoffeenews.com/2019/01/16/ ... yle-guide/

Seems interesting. .

roastimo wrote:On the other hand I'm not sure what is referred to here.
For one, a plateau on BT would imply Zero (0) value on RoR.
Otherwise a plateau on RoR--speaking again about the man who is most often mentioned--goes against a recent assertion, that a plateau on RoR goes together with a flick and results in not as good coffee as would be attained without RoR plateau and the corresponding flick.
Returning to the BT plateau supposition with corresponding Zero RoR, this would be untenable because it implies a stall. Recovering from a stall does not produce good results, I think.
So likely the description argues (versus Rao) that a plateau on RoR can be worked in well. Often I have roasted with those, and also without, but please advance which was meant, and any further information. I'm interested.

This is what is referred to here: