What variables to change dialing in a new bean?

[Micahdesign]

Hello, new to roasting on a Quest M3 and would like to know what you mostly change to test different profiles on a new bean?

I want to do 3 back to back roasts and end up at about a light/medium range (about 410-415 drop temp I'm liking so far).

To keep things somewhat simple, would you charge at 3 different temps, keeping total time, dev time and drop temp same? Or same charge temp, same drop temp but 3 different dev times, or different total roast Time?

I just did 3 roasts on a bean, same charge temp, same drop temp, each were about 30 seconds longer and various development 20% - 25% but all three just ended tasting the same (good enough) and I'm not experienced enough to see the probably subtle flavor changes.

I don't want to purposely roast anything to taste terrible, just trying to learn how to slowly change things depending on the bean.

Maybe a side question do you have 1 "default" profile you find works well on most beans and only tweaking when something tastes off? (Maybe 2 or 3 other default profiles for like Brazil or naturals)

Thanks!!

[mkane]

Try altering middle phase since dev. didn't do much. wish I could be of more help.

Roastings always a struggle and one of the reasons why it's enjoyable.

[Almico]

Drop temp is the most significant variable affecting coffee flavors. You found that out when you roasted 3 batches and changed everything but drop temp. To use an out dated radio reference, drop temp is like dialing in the station you want to listen to; most other variables just fine tune the reception.

For the next 3 roasts try keeping total time, charge temp and time to dry the same. The goal will be to drop one roast at 15* past 1Cs, the next 30* past 1Cs and the third at 45*. Forget development percentages. They're practically useless.

This is not easy to do, but it will go a long way toward teaching you how to control your roaster as well as the variety of roast levels for any coffee. To accomplish this you will have to reduce heat post dry more for the lighter roast and progressively less for the darker ones. Try keeping the RoR slope declining evenly. The slope on the lighter roast will be steeper, the middle roast less steep and the darker roast even less.

[Micahdesign (original poster)]

Wow, thanks, exactly what I was looking for!

[Almico]

These are two profiles that illustrate it well. The background is a light roast dropped around 385*, the foreground is 414*. A medium roast would drop at 400 for me, given I get 1C at 370.