What does a good roast profile look like?
Beginner roaster here. I've seen quite a few posts where people paste in their roast profile from a data logger and an experienced roaster will comment that it is a "good looking profile". I've gathered some thoughts about what this might mean but wanted to ask the open question, what are the characteristics of a good looking profile chart?
This possibly sounds like a bit of a cop-out Terence, but I think that a "good" looking profile will depend on a number of variables but predominately the type of roaster & roasting method being used, the type of beans being roasted and what you are trying to achieve from the roast. I think you will find most comments are related to the roaster and/or the beans under discussion. So possibly the best way to find your own sweet spot profile is to use one someone else has offered as a starting point, then adjust to your own setup, environment and requirements. If you have purchased an off-the-shelf roaster with a manual they tend to have a suggested profile that suits the roaster to kick you off. Other factors that could contribute are Green weight, environmental temperature & humidity, bean age/dryness etc.
But the sort of things I look for are a steady ramp-up to First Crack. And here some beans require a steeper ramp-up (Yirgacheffe possibly), and others a more gentle one. Then a gentler but steady gradient without stalling towards 2nd Crack stopping at your preferred/desired roast level. I tend to go 10-12mins to 1st Crack and then 15-17mins if I go to 2nd Crack.
Anyway that's my 2 cents worth.
GK has pretty much said it all.
What kind of set up do you have?
Post lots of details of your setup and maybe someone who has similar can post their DL sheet for you to have a starting point.
It takes lots of time, lots of greens and plenty of experimenting / recording to find what works best for you and your gear that you roast and brew with.
I agree with Steve82 about needing to know the setup. In terms of finding what's "best" for your setup, it depends on so many things!!! So ...
If you have an air-roaster that you can control (eg modded popper like me), then over on HB Jim Schulman has documented a set of starting profiles and how the sections of each tend to influence the result. You'll need to search around a bit. I haven't found anything like it elsewhere. If you find that sort of info for your type of roaster then you'll get pretty good results very quickly. After that its a matter of how picky you want to be and how sensitive your palette is (not too mention how good your brewing is).
Hey pete have you got a link to Jim's profiles? I can't login and have a proper dig?
Certainly I don't try for a steady rise.
Different things for different people.
Thank you to all. Lots of really interesting and useful thoughts.
I am using a Quest M3 - a solid drum, electrically heated roaster. I am doing 228 g loads of greens dropping to ~190 g post roasting. I was thinking about this less from a specific roaster perspective and more from a general roasting philosophy view point. For example, some of Chokkidog's posts indicate that he uses a profile where the rate of rise starts high and decreases steadily over time. Jim Schulman on Home-Barista.com has a different profile, with high charge temperature, gentle power for the drying phase, maximum power for the ramp up to first crack and then another gentle phase.
So Chokkidog's approach has no turning points. But Jim's has one turning point with rate of rise increasing significantly between 150*C and just before first crack.
I was wondering whether the graphical appearance of a "good looking profile" could be summarised by temperature gradient and number of turning points? Certainly does sound like people are suggesting that all of these issues are very roaster specific though.
I'll try and hunt down the posts I'm thinking of - the info is spread around a bit, but you don't need to log in. Just use the search item on the home page - it works well.
PS - nice you have an M3 - bit jealous here!!!
The coffee hobby thing has developed quickly for me. Wanted to limit upgradeitis for the roaster.