Sonofresco (all roasters in general) heat source

[milowebailey]

My question is how often can I safely turn on and off the burner.  My theory is at first let it run for about 2 minutes and then see if on 1 second/off one second will work.  I figure once it's hot, it will burn a little more efficiently.

I'm thinking that there needs to be multiple burners in the machine. One that's always on to maintain a minimum temp in the profile and others to boost the temps to the different levels of the profile.

With an electric heater you could just use a variac to control a powerful heat source, but I just don't see a safe way to do something like that with gas.

As long as I have more questions than answers this will remain fun!

I've googled control valves that have 2 setting... High and Low... but they are big $$$ unless I can find one on EBAY  most are used in boilers.  But even then the temp will go up and down as the burner moves from low to high and back to low.

I think Peter is correct.... the Bean will absorb some of the heat in the outer skin and when the heat turns off loose some, but also transfer some farther into the bean... what % goes where.... that's a good question...

So, you're in agreement with me then - a single hi-powered electric heat source would be more easily controlled?

No one said it would be easy

[milowebailey]

Also realized you really are measuring air temperature near the bean mass... which if you slowed down the air, your beans would not stir properly and you'd get burned beans on the bottom and not roasted beans on the top.

I was thinking of the Poppery air poppers. The CW for using them is to add enough beans that the movement is slowed or almost stopped. If the airflow in the Sonofresco could be reduced enough to slow down, but not stop, bean movement, wouldn't more of the energy be directed into the beans? If so then it should be possible to get an accurate measurement of the bean mass temps.

Let me ask this to help clarify the problem: Where do you read the temp, as it YoYo's, to determine the roast level - at the top of the curve, the bottom, or some arbitrary point in between?

The yo-yo IMO is partly due to the heat on and off for such a long time... I think if I can turn the heater on and off more often that the yoyo effect will be less (with an electric element you can do it many times a second and have great control).. With gas, it becomes trickier (that's why many chefs prefer an electric oven to gas... the yoyo effect)  But I think if you can find a good location in the bean mass to measure the temperature that more closely corresponds to the true bean temperature and switch the burner on and off more often I can get closer.... may take some experimentation.... and as Peter said it may not matter anyway....

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

[Tex]

Also realized you really are measuring air temperature near the bean mass... which if you slowed down the air, your beans would not stir properly and you'd get burned beans on the bottom and not roasted beans on the top.

I was thinking of the Poppery air poppers. The CW for using them is to add enough beans that the movement is slowed or almost stopped. If the airflow in the Sonofresco could be reduced enough to slow down, but not stop, bean movement, wouldn't more of the energy be directed into the beans? If so then it should be possible to get an accurate measurement of the bean mass temps.

Let me ask this to help clarify the problem: Where do you read the temp, as it YoYo's, to determine the roast level - at the top of the curve, the bottom, or some arbitrary point in between?

The yo-yo IMO is partly due to the heat on and off for such a long time... I think if I can turn the heater on and off more often that the yoyo effect will be less (with an electric element you can do it many times a second and have great control).. With gas, it becomes trickier (that's why many chefs prefer an electric oven to gas... the yoyo effect)  But I think if you can find a good location in the bean mass to measure the temperature that more closely corresponds to the true bean temperature and switch the burner on and off more often I can get closer.... may take some experimentation.... and as Peter said it may not matter anyway....

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

So, when are you relocating to Houston so we can collaborate more closely? 

You know, the closer and longer I look at my Sonofresco, the more similarities I see between it & the Behmor (other than the differences in robustness of build) - non-reprogrammable profiles, batch size, etc., all seem to be the same. Oh, there is one big difference: ~$300 for the Behmor & ~$3000 for the Sonofresco! 

[J.Jirehs Roaster]

You know, the closer and longer I look at my Sonofresco, the more similarities I see between it & the Behmor (other than the differences in robustness of build) - non-reprogrammable profiles, batch size, etc., all seem to be the same. Oh, there is one big difference: ~$300 for the Behmor & ~$3000 for the Sonofresco! 

THE sonofresco is worth its weight because it is so simple and when a skilled roaster determines a good roast for a specific bean then any runny nosed brat that works in the shop can roast beans as needed and clean the machine with the simplest of tools in a reasonable time..

for the geeks in us the milowidget is on its way

[Tex]

...
for the geeks in us the milowidget is on its way

You mean the much-ballyhooed but never seen milowidget? 

[CoffeeCarl]

Milow
I've only had mine for about a month, so I'm still learning alot. I read you were using 1.2lb loads and I was told by the guys at Sonofresco to use a 600gr. load. What sort of effect do you think this has on the final product ? Also I have fluke thermocouple
inserted into the bean mass and yes, the temperature drops quickly when the heater cycles off. Thats why I was wondering
if lowering the fuel pressure would help eliminate some of the cycling. It would still basically use the same curve, just maybe
smooth it out some. If I understand correctly, what your trying to do is smooth and change the curve by having the heater
cycle quicker ? I'm a bit behind on my reading so I'm sorry if these questions have already been answered.

Thanks for any imput.

Carl

[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.

[J.Jirehs Roaster]

...
for the geeks in us the milowidget is on its way

You mean the much-ballyhooed but never seen milowidget? 

If you have not seen it you didn't click on the provided link.. and if you want it in a pretty red box to match your roaster than you have to wait for the design/marketing guys to get done with that part

CoffeeCarl, if you read back a little further you will see we speculated the air temp is yoyoing but the bean temp is steadily rising...

If I wasn't so tired from laying a tile floor and didn't have so much fresh roasted coffee on hand I will drill a hole in a Uganda bean, poke my temp probe in it and take him and a mess of his buddy's up to the coffee shop and see what happens...  :sleepy2:  not today

[CoffeeCarl]

Yes, I understand thats it much easier to speculate that the internal bean temperature is constantly rising, but I'm not convinced
that this drop in temp does not affect the final product, thats all. Overall I'm very happy with mine so far, but I'm sure it could be improved. I hope Milows widget works out , I for one would be intrested. But I'm really intrested in for now is the size loads ya'll are
using, and how this may change the roast.

Thanks

Carl

[J.Jirehs Roaster]

Yes, I understand thats it much easier to speculate that the internal bean temperature is constantly rising, but I'm not convinced
that this drop in temp does not affect the final product, thats all. Overall I'm very happy with mine so far, but I'm sure it could be improved. I hope Milows widget works out , I for one would be intrested. But I'm really intrested in for now is the size loads ya'll are
using, and how this may change the roast.

Thanks

Carl

at the shop near me they use the tin can from the manufacturer... if I was roasting I would probably go by weight... I believe the factory recommendation was 1lb 2oz??  changing the weight should could control the ramp (similar to an air popper)... I would be very careful messing with the gas flow.. I believe that is a temperamental burner in the sonofresco...

[CoffeeCarl]

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

[J.Jirehs Roaster]

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

1.2 lbs = 544.? grams or 600grams = 1.3? lbs... Sonofresco says 'fill this tin can level full and roast'. The machine is such a beast it may take a bigger than expected change in the load to sway the roast profile... I also think we may be over thinking it.... Do keep in mind (if you are finding something unexpected in the flavor of your roasts) the fluid bed roasters tend to produce a brighter tasting roast than a drum roaster... that is an interesting debate all by it's self??? what method (fluid bed or drum) is better at showcasing the qualitys of a specialty grade coffee and why (boy that is a big can of worms Pandora's box you opened Mr Lamm)

[Tex]

Sonofresco recommends 1.4 lbs of greens per batch.

[milowebailey]

...
for the geeks in us the milowidget is on its way

You mean the much-ballyhooed but never seen milowidget? 

Careful mr.... those is fight'n words...

[milowebailey]

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.