Roasting Light

[Law104]

I find most high density coffees do well in this roast development range and drop temp. If I go longer and hotter, let's say to 400* it loses acidity and picks up astringency. Beyond that (415*) the acidity is mostly gone, but so is the dryness. The trick is to get it hotter faster and build the pressure in the bean early. This pressure, like a pressure cooker, helps force the heat transfer to the inside the bean quicker.

Almico thanks,
If you have the time, basically what modes (no detail requested) did you do to your roaster. Your declining ROR is impressive. I have a Diedrich IR5. I have very little control, except for gas 3-22Mbar and fan 50 and 100%(I.e two setting only). Should you have any suggestions as to what I could do to have more control over my roast, I would be grateful
.

Thank you.......

 

[almico]

My roaster has an exhaust 4 step damper with no motor speed control. I pretty much only use 50 and 75% settings. If you can find a way to get intermittent stops in the damper it would help.

Your heat range is OK as long as the safety doesn't kick off at 3mBar. I roast 8# of coffee with 5-7"WC max, so your 22mBar should be fine. I replaced my gas valve with a more precise Parker needle valve. It works a treat. You need to be able to turn the gas almost off and then finally off completely to finish the roast, depending on the coffee and roast level.

Then you just have to make sure your BT probe is in a useable place. Mine is about 7:30 on the clock face and about 2cm from the drum wall. I can roast down to 1# with good data on Artisan.

 

[Jrodanapolis]

Exactly what Musicphan said in his first post. I usually do my first gas pressure cut at 140 C, from max (~4.5 kPa) to 3-3.2 kPa. Another at 160, down to 2-2.4 kPa, a third at 180 C to 1.5 kPa, and a final one about 1 min after FCs, to coast along at 0.5-0.75 kPa while I finish up the roast. My average RoR for each phase are 22 C, 15C, 8C and 4C, for drying, Maillard, FCs and FCe, respectively. I like City roasts, so I usually end up dropping right at the end of FC, about 2 minutes of development time for a total of 10-11 minutes of roast time, following the phase numbers Musicphan gave (4-5 min for drying, 4-5 min for Maillard, and 1:40 to 2 minutes for development). If you can stretch your first crack for about 2 minutes, and drop at the end of that, or 30 seconds past FCe, I think you'll have fully developed light roasts.

Good luck! Let us know how it goes!

 

[Law104]

My roaster has an exhaust 4 step damper with no motor speed control. I pretty much only use 50 and 75% settings. If you can find a way to get intermittent stops in the damper it would help.

Your heat range is OK as long as the safety doesn't kick off at 3mBar. I roast 8# of coffee with 5-7"WC max, so your 22mBar should be fine. I replaced my gas valve with a more precise Parker needle valve. It works a treat. You need to be able to turn the gas almost off and then finally off completely to finish the roast, depending on the coffee and roast level.

Then you just have to make sure your BT probe is in a useable place. Mine is about 7:30 on the clock face and about 2cm from the drum wall. I can roast down to 1# with good data on Artisan.

Almico thank you for the reply, I am going to roast with my damper at 50% and 75%, the 75% will be an approx setting, as there is no dedicated indent for this setting. I will let you know if this helps.

 

[Law104]

Exactly what Musicphan said in his first post. I usually do my first gas pressure cut at 140 C, from max (~4.5 kPa) to 3-3.2 kPa. Another at 160, down to 2-2.4 kPa, a third at 180 C to 1.5 kPa, and a final one about 1 min after FCs, to coast along at 0.5-0.75 kPa while I finish up the roast. My average RoR for each phase are 22 C, 15C, 8C and 4C, for drying, Maillard, FCs and FCe, respectively. I like City roasts, so I usually end up dropping right at the end of FC, about 2 minutes of development time for a total of 10-11 minutes of roast time, following the phase numbers Musicphan gave (4-5 min for drying, 4-5 min for Maillard, and 1:40 to 2 minutes for development). If you can stretch your first crack for about 2 minutes, and drop at the end of that, or 30 seconds past FCe, I think you'll have fully developed light roasts.

Good luck! Let us know how it goes!

Jrodanapolis thanks, I will keep you updated.