OK, here's the problem. I used to roast with a Gene which measured temps of exit hot air afaik. Then I roasted a wile on a homebuilt roaster without temp measurements. Now I'm roasting on my new roaster which has 2 points where the temp gets measured. One probe is in the beanmass, the other just below the drum, a bit left so it's not directly above burner.
I've done a couple of roasts now and used Greenbean's nifty app to log them.
The roasts were all a bit uneven, so I'll speed up the rpm of the drum so the beans get mixed better.
I started roasting, gradually adding more heat until I got at a chamber temp of about 255. I kept it there untill 1th crack started (about 188 beanmass) at which point I left the burner on that level. A bit before 1th crack I noticed a drop in chamber temp, for which i compensated with som extra heat. It then was steady until start of 1th. The chamber temp rocketed as soon as 1th crack was rolling until it reached a 289 at start of 2nd.
Time is in minutes, CT = Chamber Temp, BT = Bean Temp
Am unsure on how accurate the temperature of beanmass is.
Amount roasted 1Kg
Time......CT.........BT
0..........8.............8
1..........100.........18
2..........170.........37
3..........206.........58
4..........231.........78
5..........236.........102
6..........250.........120
7..........256.........136
8..........257.........152
9..........257.........166
10.........257.........179
11.........258.........188
12.........262.........200
13.........288.........209
14.........290.........221
1th @ 10m48s, CT 257, BT 186
2nd @ 13m20s, CT 289, BT 218
Dumped @ 14:00
Result: too dark, shouldn't have taken them 40s into 2nd
All in all I got the feeling roasting time was quite short and the time between 1th and second was short as well.
So what's the time between 1th and 2nd on other drum conduction roasters, anyone ? How long shoul such a roast take in total ? Is there someone who could tell me why the chamber temp dived before, and rocketed at 1th crack ? Any comments on my profile in general ?