Sonofresco (all roasters in general) heat source

[milowebailey]

Thanks J

I got the 600gr. load recomendation from Sonofresco, thats why I was wondering about the 1.2lb load that Milow refered to.
 
Carl

My bad.... 1 lb 2 oz... is what I use... my mind was thinking 1.2..... sorry about that

[J.Jirehs Roaster]

Sonofresco recommends 1.4 lbs of greens per batch.

That would be
1.4 pound = 635.029 318 gram batch... as apposed to
600 gram = 1.3227735731 pound batch or
1.2 pound = 544.310844 gram batch...   my point is the
91 grams = 0.200 620 658 59 pound = 3.209 930 537 4 ounce difference is not soo much for that roaster to push around and I don't think it will make a big difference but I guess if you got the greens you could roast three batches to say a setting of (3) on the same day (better roast a batch of control beans to preheat the roaster or let it cool all the way down between roasts) with the same ambient temp and humidity then do a blind cupping of the three roasts to see if there is any difference...

[Tex]

Tex... you are down the same rabbit hole I've been toying in for some time... I appreciate your questions and comments

I'm seriously thinking of trying an electric heater in place of the burner. It'd then be a piece of cake to profile using a PID & a variable speed fan.

Tex

The Sonofresco uses 31000 BTU propane burner... 9085.5 watts ... you need one huge power source which in bigbird terms is a little over 40 amps at 220 volts... with a fluid bed you need huge heat.

I've not looked at the specs enough to determine the applicability of this, but this is sort of where my thinking is headed.



Screwy link - try this one instead

[ButtWhiskers]

The Sonofresco uses 31000 BTU propane burner... 9085.5 watts ... you need one huge power source which in bigbird terms is a little over 40 amps at 220 volts... with a fluid bed you need huge heat.

So maybe a 100k btu forced air propane heater with 300+CFM air flow

and a 6-8" x 24" piece of stainless steel pipe could make a guy a "Papafresco"
for under $200...


I bet a guy could do 5#+ with a setup like that...

[Tex]

The Sonofresco uses 31000 BTU propane burner... 9085.5 watts ... you need one huge power source which in bigbird terms is a little over 40 amps at 220 volts... with a fluid bed you need huge heat.

So maybe a 100k btu forced air propane heater with 300+CFM air flow

and a 6-8" x 24" piece of stainless steel pipe could make a guy a "Papafresco"
for under $200...


I bet a guy could do 5#+ with a setup like that...

You're shooting for a 30 second roast profile, right?

[ButtWhiskers]

You're shooting for a 30 second roast profile, right?

Hey, add in a milowidget, a couple of solenoids, and a laptop and I bet you'd be able to get a better profile than a stock Sonofresco.

[Tex]

You're shooting for a 30 second roast profile, right?

Hey, add in a milowidget, a couple of solenoids, and a laptop and I bet you'd be able to get a better profile than a stock Sonofresco.

And if that doesn't work out you can use it to remove tats from gang members!

:violent5:

[Tex]

OK, this thread is diverging from where I hoped it would go. The confusing thing about Sonfresco's (and probably any fluid-bed roaster) heat/air flow source is that when the burner and blower are both on the air temp readings in the bean mass are way higher than the bean temps themselves. When the burner is off and just the blower is running the opposite is true.

My point is/was, how can you roast to a specific bean temp when the air temp around the beans is fluctuating so widely and so often? As someone pointed out to me, there are standards that can be used to accurately determine specific roast levels. If I want a pure City roast, I'd look for the beans temp to be at a specified level (actually that is bean mass temp since to measure the temp of the beans you'd have to have a probe inside a number of beans to be able to statistically state the temp of all the beans).

Unless someone can show me how to do this I'll stick to my contention that the temps are meaningless as a roast level indicator if they can't be used to judge exactly when a City roast is turning into a City Plus. That leads to my argument that the only true test of roast levels is time, color, and sound.

So if the temps aren't of any use in determining specific roast levels, what's the point of measuring temps? I say the only use for temp measurements is to develop and use different roast profiles. That assumes all beans have the same physical make up, but knowing what they say about assume makes me question this. Is it possible that if one batch of SO beans reaches the end of 1st crack at 400?F (temp reading placed at an arbitrary point in the air flow, not the actual bean temp), that each and every bean in my pantry will reach the same roast level at precisely the same temp, and in the same time frame?

That seems to be the premise of fluid-bed roasters like the Sonofresco. The use of air flow to stir the beans causes the temp of the bean mass to be non-representative of the temp of the beans. The air temp in the bean mass fluctuates so much that consistent temp readings can only be made at a significant distance from the roast chamber. While this is useful in creating and using  roast profiles, it's worthless as an indicator of roast levels themselves.

[peter]

My point is/was, how can you roast to a specific bean temp when the air temp around the beans is fluctuating so widely and so often? As someone pointed out to me, there are standards that can be used to accurately determine specific roast levels. If I want a pure City roast, I'd look for the beans temp to be at a specified level (actually that is bean mass temp since to measure the temp of the beans you'd have to have a probe inside a number of beans to be able to statistically state the temp of all the beans).

Unless someone can show me how to do this I'll stick to my contention that the temps are meaningless as a roast level indicator if they can't be used to judge exactly when a City roast is turning into a City Plus. That leads to my argument that the only true test of roast levels is time, color, and sound.

So if the temps aren't of any use in determining specific roast levels, what's the point of measuring temps?

Are you asking that only in terms of the Sonofresco?  You must be, because on roasters where bean temps can be measured accurately, knowing bean temps and using them to judge roast levels is paramount.

I just think you're over-thinking the temperature swings you're seeing, and assuming that the beans are changing drastically.  Evidently, the Sonofresco works well, and so my guess is that they worked backwards from the roast level they wanted and programmed their roaster off of that by extrapolating bean temp from measured air temps.

[Tex]

Evidently, the Sonofresco works well, and so my guess is that they worked backwards from the roast level they wanted and programmed their roaster off of that by extrapolating bean temp from measured air temps.

That's my point Peter - it works well IF their roast profile suits your taste. But what if you want a bean that's 10?F hotter or cooler than what they pre-program? Their profile is worthless then, and you're back to square one, trying to determine roast level by time, color, and sound. There are no variables you can adjust to fine tune their programs.

I love my Sonofresco, but other than my first batch, I've never relied on the programs. I listen for first crack and time the roast from that point. For 1.4 pounds of greens I use the #6 profile, knowing that long before the machine does so, I'm going to shut the gas off when I sense the roast is right.

The Ambex like the one I may be getting, is similar in that regard; you still have to monitor roast color and listen for the sounds. But one advantage it has is a thermometer in the bean mass that seems to reflect the actual bean temp. That's what I'm missing in the Sonofresco, a tool that helps me predict the approach of a given roast level.

[milowebailey]

Tex

With the setup on my sono I think I can accurately measure temperature and stop the roast constantly.   Albeit it's not the exact temperature of the beans, but I find it to be just as described in this article from Sweet Marias

I also use profile #6 most of the time unless I'm going Vienna

With my thermocouple down in the roast chamber as described above 1st crack happens at about 395 - 405 degrees (burner on) every time. 

and Full City + is when my thermocouple measures ~450 (burner on).  But that is only true when I use 1 lb 2 oz of green.    Also I use the temperature when the burner is on.

[Tex]

Tex

With the setup on my sono I think I can accurately measure temperature and stop the roast constantly.   Albeit it's not the exact temperature of the beans, but I find it to be just as described in this article from Sweet Marias

I also use profile #6 most of the time unless I'm going Vienna

With my thermocouple down in the roast chamber as described above 1st crack happens at about 395 - 405 degrees (burner on) every time. 

and Full City + is when my thermocouple measures ~450 (burner on).  But that is only true when I use 1 lb 2 oz of green.    Also I use the temperature when the burner is on.

I hear what you're saying, but I guess I'll need a lot more roasts under my belt before I figure out the best placement of the t/c in the roast chamber. It's encouraging though, that you're getting such precise controls of your roasts - it gives me cause to hope.

[J.Jirehs Roaster]

Tex

With the setup on my sono I think I can accurately measure temperature and stop the roast constantly.   Albeit it's not the exact temperature of the beans, but I find it to be just as described in this article from Sweet Marias

I also use profile #6 most of the time unless I'm going Vienna

With my thermocouple down in the roast chamber as described above 1st crack happens at about 395 - 405 degrees (burner on) every time. 

and Full City + is when my thermocouple measures ~450 (burner on).  But that is only true when I use 1 lb 2 oz of green.    Also I use the temperature when the burner is on.

I hear what you're saying, but I guess I'll need a lot more roasts under my belt before I figure out the best placement of the t/c in the roast chamber. It's encouraging though, that you're getting such precise controls of your roasts - it gives me cause to hope.

I started with this threads terminology

City Roast;  1st Crack has just ended, maybe a pop or two still going on,
                 roast is stopped.
City Plus;   1st Crack is completely over, no more pops, temps are maintained,
                 or increased slightly.
Full City;     Roast progresses in temp and color, 2nd crack is imminent,
                 with a snap or two, smoke odor shifts.
Full City +   2nd Crack has actually begun, but has no momentum, is not rolling.
Vienna        2nd Crack is established, ~20sec. into 2nd crack.
French        2nd Crack is at least half-way through, roughly at its peak.

and started tracking the temp of my roast (different roasters and or different probe location different temps) I am still learning... the placement of the t/c in the chamber is not as important as its consistent presence in that spot.. I think what milowebailey for got to say after he said he always roasts on (6) in his sonofresco is that then when he reaches the level of roast he wants he turns off the gas switch to stop the roast...

[Tex]

... the placement of the t/c in the chamber is not as important as its consistent presence in that spot.. I think what milowebailey for got to say after he said he always roasts on (6) in his sonofresco is that then when he reaches the level of roast he wants he turns off the gas switch to stop the roast...

I've got a handful of 12" x .125" diameter, 'type T', s/s Omega probes. I'll rig up a way to suspend one through the flue so it'll be located in the same spot each time. Maybe the s/s sheathing and the ungrounded t/c will negate some of the YoYo effect?

I picked up the Dude's reasoning for using the #6 setting, and I've been doing the same since we discussed it in another thread. I call it City roast when I hear the outliers of 1st crack but before the first 2nd crack outliers. This works pretty well but I'm a control freak and using sound is a bit imprecise. That's why I'm obsessing about a more predictable way to measure bean temps.

Here's an observation: I roasted a Yirg Koke yesterday - the same one I've mentioned before that I had problems achieving an even color. That was using the UFO/CO.

With the Sonofresco I was wondering;
* Would the 1/4" beans reach temp more quickly than the 1/2" beans.
* Would the outliers be spread even more widely because of the variation in bean size?

Answer;
It didn't seem to matter. The outliers were no more noticeable with this batch than it was with a batch of Brazilian beans that were more carefully sized. So if bean size didn't exacerbate the outliers situation, why not? Are the smaller beans harder than the bigger beans, giving them the same mass as the larger beans? I might have to dig some of my fracture testers out of mothballs to see if there's a density thing going on here. Hmmmm

Bottom line: This yirg roasted nice & evenly to a light City roast by stopping the roast as the 1st crack outliers were sounding off. The cup of vac pot I had for my cafe au lait was very fragrant and clean tasting. The aftertaste was pleasant and long-lasting. According to my notes I like this bean roasted lighter, so next time I'm going to stop the roast just as the 1st crack starts to slow down.

I'm seeing some progress with the Sonofresco.

Thanks for your help!

[7over]

I'm not familiar with the Sonofresco... but I have built and am perfecting my own Fluid Air Bed roasting machine for commercial production use in my roasting plant.

I'm curious about what 'profile #6" looks like. Do you know or have you plotted exactly what that is? Is it based on bean temps alone? bean temps over specific times? or air temps? Does the Sonofresco control the ramp rate of the beans directly during the roast and compensate for faster and slower ramps or does it just blow varying degrees of hot air until the beans get to certain predefined set points?

I've placed my bean temp probe in the densest part of the bean mass just before the beans enter the air stream. My software averages the recorded bean temps over 2 second rolling intervals so that I don't get the wild jumps that too frequent reporting tends to generate.

So far, the roaster and software is working well together but I am going to upgrade the electric heating element to a larger unit so that I can roast more than 3 lbs per batch.

Anyway, I'll update the board as I make progress but I am curious about what "profile #6" is.

What can you tell me?