Bunkmil wrote:And what's your total roast time range ?

My guess is that with such batch size you won't be able to roast under 12-14 minutes. Is that correct ?

Correct, but with a slow start machine such as the Behmor I don't find that it matters. I've stopped trying to apply advice for commercial drum roasters to the Behmor and have just tried different roast parameters and decided for myself what works best. I've read the Rao and Hoos books on roasting but didn't find a lot of direct application for my roasts on the Behmor.

For last year's Focus on the Roast competition, (the last roasts I have data for here on this computer), the roast times for the six roasts I did at 300 grams ranged from 13:18 to 15:18. I deliberately worked on both sides of my roasting parameters to shorten or extend the roast and change it up to pick the best roast to send in. I sent in the 3rd roast which hit first crack at 11:12 and I hit cool at 14:12.

More detail on these roasts and how I roast in my Behmor here: Roasting Competition by Mill City Roasters - Discussion Thread

These days I'm pre-heating longer and starting hotter so my roast times may be shorter. I need to save my RoasterThing database to DropBox so I can view more recent data when I'm away from home.

yakster wrote:Correct, but with a slow start machine such as the Behmor I don't find that it matters. I've stopped trying to apply advice for commercial drum roasters to the Behmor and have just tried different roast parameters and decided for myself what works best. I've read the Rao and Hoos books on roasting but didn't find a lot of direct application for my roasts on the Behmor.

You're right. I think that trying to replicate commercial drum roasters curves to the Behmor just don't work.

yakster wrote:For last year's Focus on the Roast competition, (the last roasts I have data for here on this computer), the roast times for the six roasts I did at 300 grams ranged from 13:18 to 15:18. I deliberately worked on both sides of my roasting parameters to shorten or extend the roast and change it up to pick the best roast to send in. I sent in the 3rd roast which hit first crack at 11:12 and I hit cool at 14:12.

More detail on these roasts and how I roast in my Behmor here: Roasting Competition by Mill City Roasters - Discussion Thread

Wow I think I have never tried a 3 minutes development time! Have you dropped the temperature during or after the first crack in order to stay away from the second crack ?

yakster wrote:These days I'm pre-heating longer and starting hotter so my roast times may be shorter. I need to save my RoasterThing database to DropBox so I can view more recent data when I'm away from home.

Feel free to share

I've dropped the temp after first crack, but not as much as I used to before the Behmor+ upgrade. I used to do the door dance with the original board and I had to re-learn how to roast after the Behmor+ upgrade because the temps I was seeing logged with the door dance would drop pretty fast but probably were not reflective of the BT temps. Once the afterburner kicks in and my ET peaks I usually trim my Variac to a certain temp and then I'll start to drop the temp for a declining ROR (though I'm not really monitoring ROR, just temps) when first crack is established. Sadly, I haven't been roasting as regularly as I used to because of other priorities but I'm forcing myself back into it and reassessing my roasting profiles so I don't want to give specific advice. I also find that when I've tried to give specific advice that it didn't seem to map very well to other's Behmor roasters, maybe because of the differences in the age and condition of the machines, the old style chaff tray, the Variac, etc. I'm a big fan of going back to doing multiple roasts and changing one variable at a time and picking the best roast from time to time.

When I was playing with a Plus to try and understand how it worked I seem to recall that every time you pushed a P button, the counter started anew with the elements on so when you press the button is significant if you're trying to go back and forth to get a middle setting. Likely you want to select a new setting just as the elements turn back on.

Ira

And do you remember what's the P4 cycle?

I thought I remembered Joe Behm saying that that didn't happen, but if you cut the power down to zero and then brought it up that you would start a new cycle... recollection on this is hazy, though.

If you want to know how it works, watch it. That's what I did and that's how I found out. At that level of detail, nothing matters as you have to be "abusing" the system to be at a place where that information matters.

Ira

ira wrote:When I was playing with a Plus to try and understand how it worked I seem to recall that every time you pushed a P button, the counter started anew with the elements on so when you press the button is significant if you're trying to go back and forth to get a middle setting. Likely you want to select a new setting just as the elements turn back on.

Ira

I found that it worked like this; when I change from one manual heat setting to another, it finishes the current cycle, then switches to the new cycle. This means if you are a bit late to the button you could have to wait up to 15 seconds before the change is registered. It looks like the cycle is 15 seconds on for P5, 10.75 on followed by 4.25 off for P4, 7.5 and 7.5 for P3, etc. While I was experimenting with 82.5% I would hit P5 when the element turned off for P4, then press P4 again 15 seconds later. It was reasonably easy to keep things smooth that way, and you didn't really risk missing a change. If or when I get around to installing controls I'll just run a PID on chamber temp, measured with my probe at center bottom, sitting on top of the back edge of the chaff tray. With likely the PID setpoint following a preset curve, partially limited by the ability to heat.

I agree that this machine is begging to be PIDed. Pressing buttons every 15 seconds AND compensating for the afterburner fan cool down effect sounds like it would require constant attention and flawless execution.

Even when attempting to do the simple P4 roast the other day I accidentally pressed P5 and zoomed up to about 305F before I realized my error, and then switched to P3 for the remainder of the roast, so I did an accidental FSSF roast (although I don't get why this would be properly termed "slow finish"). The beans came out just fine, but I didn't roast another batch at P4 to compare them to. Anyway, I think that I'm likely to make more fat-finger mistakes if I need to do something every 15 seconds.

How can we determine if P4/P5 every 15 seconds results in a better roast than simply using P4? Is this a question of personal taste that we each need to attempt to answer for ourselves using our taste buds, or is there any objective measure of roast quality that would apply to all of us?

I have learned to view the kicking in of the afterburner fan at 7:30 on 1 lb setting more as a balancing act between thermal radiation and convection. I think what is critical is where you are in the roast when this occurs. Naturals and honey processed will be closer to EOD than washed in my experience. The 30 seconds after the afterburner kicks in is when I decide on how much lower I will adjust my heat level to get to 1st crack. I have a different heat level controller so I can't say how that would translate in Behmor Plus manual mode but it is perhaps a bit higher than the P4 level. 30 seconds into 1st crack would require further reduction of heat until rolling cracks starts to fade. What I do after depends on the desired roast level but increased heat level is involved before hitting the cool button.