GC7 wrote:Alan - I'm not sure what this means. 220* is heat. 500* is more heat.

What's the best way to get from A to B. A is your raw green bean and B is a bean at the cusp of second crack?

It means darkness of roast is far more heat dependent than time dependent. You can roast beans at 200* for an hour and they will not get dark. You can roast beans to 475* in 4 minutes and they will be burnt.

If I want to roast darker, I drop hotter, not longer. My light roasts go for a bit shy of 10 minutes to 385-390*F. My "dark" roasts go for about 10 minutes to 415*F. I don't roast into 2nd crack. My dark is another's medium. Although lately I've been tempted to char a roast just for kicks.

Almico wrote: If I want to roast darker, I drop hotter, not longer. My light roasts go for a bit shy of 10 minutes to 385-390*F. My "dark" roasts go for about 10 minutes to 415*F. I don't roast into 2nd crack. My dark is another's medium. Although lately I've been tempted to char a roast just for kicks.

Thanks.
Question: Is your 10 minute time goal the same on your large multi-Kg roaster as it is if you roast 300-500 gm?

keno wrote:Vince, it really depends on what you want to accomplish. Roast level defined by color is a function of end temp and time. You can do a dark roast fairly quickly with a higher end temp or with a lower end temp but longer development time.

Check out this study which looks at the chemical and sensory differences in coffee all roasted to the same level (Agtron 76) using different profiles to get there: The Effect of Roast Development Time Modulations on the Sensory Profile and Chemical Composition of the Coffee Brew as Measured by NMR and DHS-GC-MS

Even though this represents a medium light roast I still think the take home message holds for somewhat darker roasts:

Thanks for the input Keno, yea my end goal is to get the nutty and chocolate but minimize the bitter and roasty as much as possible. I understand that roasty will probably come with the territory of going darker, but I'd like to keep it down as much as is possible.

Brewzologist wrote:I seldom go past 420F drop temp which is FCs+35F on my rig. For that to work versus a light roast of the same bean, I shoot for a slightly lower peak BT RoR followed by a shallower decline and enter FCs around 20-23 F/min. This usually works for well behaved beans. I'm too chicken to go further and don't bother since I like lighter 'dark' roasts anyway.

Now that is interesting, I'd have figured the same or slightly higher max ror with a slightly shallower slope to end with a higher ROR at first crack and higher temp possibly at the same DTR.

Almico wrote:It means darkness of roast is far more heat dependent than time dependent. You can roast beans at 200* for an hour and they will not get dark. You can roast beans to 475* in 4 minutes and they will be burnt.

If I want to roast darker, I drop hotter, not longer. My light roasts go for a bit shy of 10 minutes to 385-390*F. My "dark" roasts go for about 10 minutes to 415*F. I don't roast into 2nd crack. My dark is another's medium. Although lately I've been tempted to char a roast just for kicks.

This will be the way I roast my next few batches. I'll aim for 410-415-420 drop temps and compare at about 20-25% DTR. As close to 20 maybe as I can.

GC7 wrote:Thanks.
Question: Is your 10 minute time goal the same on your large multi-Kg roaster as it is if you roast 300-500 gm?

It is. But I only use my Cormorant for sample roasts. If I do the uber dark roast I've been itching to try, I'll be using the Cormorant. I don't want to burn 8# of beans.

Vince_in_Montreal wrote:This will be the way I roast my next few batches. I'll aim for 410-415-420 drop temps and compare at about 20-25% DTR. As close to 20 maybe as I can.

My Artisan is set up to reach 1C at 370 and at that setting, 2nd crack typically starts around 418*F. If I was doing a true dark roast with a rolling 2nd crack, I would probably need to go to 422-425.

Almico wrote:It is. But I only use my Cormorant for sample roasts. If I do the uber dark roast I've been itching to try, I'll be using the Cormorant. I don't want to burn 8# of beans.

Again, thanks. I like to look at the Royal Crown Jewels reports for their offerings including sample roasts on different machines. All their roasts where they report their tasting notes are very short. This had left me puzzled about roast times for those batch sizes that I guessed were 300 gm or so. Any feedback about this discrepancy?

Edit - As a note to the Hottop user above. I roasted on a HotTop for over 10 years before switching to a Bullet a few months ago. The HotTop does not have enough power to roast their stated batch sizes efficiently. Alan explained your problem well. By the time I sold my HotTop I was using 215 gm batch sizes. This helps a lot. Even then you need to be sure the temperature of the beans you add to the heated roaster are not too cold or your dry time will be too long.

I don't follow Royal Coffee. I sometimes watch their webcasts, but find them "less than helpful", to put it kindly.

Was your Hot Top edit meant for this post? Looking for feedback on my roasting profile: light roast costa rican terrazu

Yes it was. Thanks. I was looking at both and mistakenly thought the poster had answered above in this discussion..