Sonofresco / Q&A / Tip & Tricks

[Joe]

Hi All,
I just found this site and thread trying to find out as much info about the Sono I recently acquired.  Thanks to all who have posted over the years here for all the informative info.   I now have about 15 roasts under my belt and wanted to see how my findings correlate to others.
I have a 2 pounder with the ADR and Bluetooth.
I load it with ~1100g of green beans
I've been roasting outside with no vent or chimney on the roaster.
I typically hit 1st crack at about 175C (347F) and 2nd at about 200C (392F) does that seem normal?
Thanks,
-wes

No that doesn’t sound right. What elevation are you at? You might want to call Sonofresco and have the Tech walk through any procedures to get the temps corrected. 400f should be 1st and 430-440 should be second depending on bean, altitude etc. also i am jot familiar with the 2 lb model but for the 1 lb i use 1 lb 3 oz and if i had a 2 lb i would try 2lb 6 oz for my load. But there are all kinds of valve adjustments and a cover on a fan to be removed if you are at any significant altitude. John is at like 5000ft above sea level and had to remove the cover for more airflow.

[Ascholten]

It could be your temp thermocouple out of whack too, out of place or something.  Although I do not own one of these, I do have to agree with Joe that yes, in ANY roaster really, those temps are pretty low.

Aaron

[wajacos]

Hey Joe, Ascholten,
Thanks for the quick responses.  I'm pretty much at sea level and the beans seem to have a good loft and the roaster is following the Program set in the software, but I'd like to check to see if there is a plate obstructing airflow, do I need to pull the whole thing apart (I did buy it used, should there or should there not be a plate in there for roasting at sea level)?  I checked the resistance of the RTD and it seemed to be fine it was rather old the wires a little fried so I have an extra so I went ahead and replaced it.  Joe, the temps you stated are those temps within the bean bed or are those temps as read from the RTD/ Sono controller?
Thanks again for all the advice.
-wes

[Joe]

Hey Joe, Ascholten,
Thanks for the quick responses.  I'm pretty much at sea level and the beans seem to have a good loft and the roaster is following the Program set in the software, but I'd like to check to see if there is a plate obstructing airflow, do I need to pull the whole thing apart (I did buy it used, should there or should there not be a plate in there for roasting at sea level)?  I checked the resistance of the RTD and it seemed to be fine it was rather old the wires a little fried so I have an extra so I went ahead and replaced it.  Joe, the temps you stated are those temps within the bean bed or are those temps as read from the RTD/ Sono controller?
Thanks again for all the advice.
-wes

Call Sonofresco they will walk you through it. I don’t have the 2lb so i can’t tell you my experience.

[Ascholten]

There really should not be anything 'special' you need to do to roast at sea level, as that sort of is the 'default' for most everything.

Try giving them a call, they might be able to walk you through some basic stuff, or an e mail to their tech support may be useful too.
Again, I do not have one of these so can not give you first hand knowledge.
Sorry about that but will do what else I can to try to help.

Aaron

[askat1988]

With my Sono 1 lb. I typically hit 1st crack at about 356F @ ~7:30

[Ascholten]

That makes me wonder where exactly the temperature is being measured at then?  That seems pretty low to be bean mass temp.  even the old I roast would need close to  400 degrees to start cracking.

Aaron

[askat1988]

The temperature gauge is a couple inches above the beans so I guess it's just measuring air.

I have the ADF feature like the person who was asking the question.

[wajacos]

Sorry for the late response, Covid-19 equals Chaos-2020.
So here are two references buried in blogs on Sonofrescos site about 1st and 2nd crack temperatures.  The Temp probe is an RTD1000 2wire probe and is placed in the top of the flue above the chaff collector.  There is a metal diverter plate in the top of the chaff collector besides pushing the chaff to the sides I believe it acts as a heat shield to give more even readings.  I believe this is where the differential between what us sono users are seeing compared to the published data for 1C and 2C temps.

https://sonofresco.com/the-different-stages-of-green-coffee-bean-roasting/#:~:text=First%20crack%20usually%20occurs%20when%20the%20beans%20reach%20180C%20(350F).
https://sonofresco.com/how-to-use-advanced-definition-roasting-adr-to-improve-your-roasted-coffee/

[Ascholten]

Good info waja  thank you for that.

Anytime the thermometer is not actually immersed in the beans it's very hard to get an accurate bean temp really.  The slightest diversion or turbulence etc in the airflow can greatly affect the accuracy of what is being picked up.    Even roasting in cold climates, if the tc is very close to the edge of the roasting chamber it can throw it off.  Stuff gets picky on us ..

Aaron

[brianmch]

Another issue, albeit starting to get a little weedy, is thermocouple size and response rate.  I've heard they go bad but IDK bout that. 

I know, I know, save the snark.    For SOME folks who are dabbling in automation it is or can be an issue. 

[Ascholten]

It should really take a while for a TC to go bad id think,  ...  on the size .vs. response well you are not going to put a thumb sized tc in there, so with that, if it took a second or 2 seconds to react, Given the process, that bit of delay is insignificant really.  But for what its worth yes thinner is faster response,   if you want ultimate response just twist the two wires together and drop them in, can't get faster than that.

Aaron

[David (PalateOfAnAardvark)]

Does anyone have any experience using one of those infrared thermometers?

[Ascholten]

yes, they reflect off shiny metal, so stainless / aluminum can be a problem.
They are NOT pinpoint accurate, its more of like a half inch, that expands as it gets further area it looks at.
Otherwise they are pretty accurate if you can get them shining right on the beans w/o any inteference.

Aaron

[David (PalateOfAnAardvark)]

Thanks, I bought a couple of those for smoking meat and they are less than useful because it is the internal meat temperature that is important. Coffee beans are smaller, so I think, if you can get close enough to the bean, they would be more accurate.

BTW, I bought all the components for a PID temperature controller for my smoker. It wasn't practical at the time, given the smoker build I have, but I have the wiring, the thermocouples, the controller, the AC/DC stepdown components, all of it. Maybe I'll try and see what I can do between now and getting a vaccine jab.