Gene Café roast profiles

[kjeldsen]

Hey everyone.

I've roasted about 25 batches on my Gene sofar, and i've still got alot to learn in the world of roasting. I wanted to start a post about roast profiles for the Gene Café, and maybe get some input from more experienced roasters. Which profiles are you using for various coffees? I'll go first!

I've got 3 different profiles i'm toying with, basically trying to vary the curve from yellow tan stage to 1st crack, rushing it a bit for more acidity.

This first one is a profile i'm using for South american coffees primarily at the moment.

#1
1) Preheat to 200 for 10 minutes. Emergency stop - greens in.
2) Temp has dropped to about 150. Stay at 150 for 5 minutes for drying.
3) Bump to 225 for 5:30
4) Bump to 250 for 3 minutes (End of this stage is 1st crack, ususally consistent around 13:30-13:45)
5) 240 for the remainder of the roast towards 2nd crack

Notes: My current issue with this profile is that it takes too long to reach 250 from 225 over a course of 3 minutes. I've tried to remedy that by adding another stage between stepp 3 and 4, but results are inconsistent and i can't yet determine if i really need to let the roast ride 250 for a while, or if a bit lower temps will do (i've logged 245-246 as the max i've reached during 3 minutes after bumping to 250). The alternative profile is:

#2
1) Preheat to 200 for 10 minutes. Emergency stop - greens in.
2) Temp has dropped to about 150. Stay at 150 for 5 minutes for drying.
3) Bump to 230 for 4 minutes
4) Bump to 240 for 1,5 minutes
5) Bump to 250 for 3 minutes
6) 235 for the remainder of the roast towards 2nd crack

The general idea of all the profiles i use is to vary the temperature curve up untill 13,5 minutes of the roast which seems to be where most, both african and american beans, crack for the first time in the gene (using 5 minutes of preheating), after which i turn it down for the remainder of the roast.

The third profile i'm experimenting with is a variation on the first, and having roasted some fazenda yellow bourbon identically using profile 1 and 3, profile 1 definately brought out more chocolate and #3 more acidity, and may be very good for african coffees.

#3
1) Preheat to 200 for 10 minutes. Emergency stop - greens in.
2) Temp has dropped to about 150. Stay at 150 for 5 minutes for drying.
3) Bump to 225 for 4 minutes
4) Bump to 240 for 2 minutes
4) Bump to 250 for 2:30 minutes
5) 240 for the remainder of the roast towards 2nd crack

Which profiles are you guys using? What're your experiences?

Maybe Steve can even chime in with some expert advice here : ) Would be appreciated.

Cheers!

[Stephen Leighton]

I haven't used a Gene for over three years, so my experience is limited with this roaster.

What I remember it was very difficult to profile roast on as the bean mass temperature had far more influence on the profile than the dial with the temps. They are also very voltage sensitive so one thing that works for one may not for another.

But the principles on the profiles you posted all make sense why you would do them, and if they taste good that's the most important. Would be interesting to see what current and more experienced users than I are finding, but I would always keep in mind each machine will behave with tolerances and with differences.

[kjeldsen]

What I remember it was very difficult to profile roast on as the bean mass temperature had far more influence on the profile than the dial with the temps. They are also very voltage sensitive so one thing that works for one may not for another.

...

Would be interesting to see what current and more experienced users than I are finding, but I would always keep in mind each machine will behave with tolerances and with differences.

That's very helpful Steve, thanks. I have noticed that sensitivity you speak of. The roasts do taste really well, and i do feel i can vary the results, but i suppose there IS a limit when using a home roaster like the Gene.

I'm interested in knowing more about roasting on the huge probat roasters you're using, if you've got the time at some point, and if it's not spoiling too many company secrets! i'm sure other roasters are interested in knowing more about that : )

Cheers,
Martin

[Stephen Leighton]

There is a list on my computers that says instructional video on roasting, but its a huge list, but one day for sure. No secrets everything is to share.

[kjeldsen]

Brilliant! Looking forward to it then

/Martin

[daveyb]

You will find some useful stuff on nGene roasting here
http://creator.zoho.com/davec_coffeetim ... m:roastlog
Click on coffee roasting reports then detailed