Temperature off on thermostat


#1

I’ve done two brews so far on my Robobrew v3. I notice that when I cool the wort, I can get it down to 80, according to the thermostat, and I don’t understand why it’s not cooling more than that. Both times I brewed, I just decided to just transfer to the fermenter because despite cold water going through the chiller, it didnt cool any more. What I realized was, the thermostat temp might be off. As soon as I transfer the wort, the thermometer on the bucket shows about 65 degrees. that’s a 15 degree difference. And it makes sense, as far as why it isn’t cooling any more. Now I know the bottom of the robobrew is still cooling off, but I feel like it can’t be that far off, especially with me constantly stirring the wort. Is there something I am missing here? I don’t have a floating thermometer or an infrared thermometer. Now I wonder about the accuracy of the mash. thanks!!


#2

15’F is a big error for a probe-type thermometer. I would believe up to +/- 2DegF, any more is an error in measurement technique (i.e. the wort at the probe is really at the temp it says, but you are measuring a different temp at a different spot then blaming the probe).
My recommendation is to spend $15 to $25 on a probe type thermometer. I checked Amazon, water proof NTC’s for $15 (good enough for you, probably the same probe that is in the RB system) and thermocouples meters for $22 (ideal). The mash, wort and fermentation temperatures so too important to leave to chance, you’ll never make the same tasting beer twice.
Spend $22, get a nice thermocouple probe, use it as your gold standard.
To check your Robobrew accuracy you’ll want to compare the 3 points you care about (70F, 150F, 212F), if they are off then write in permanent marker on the side of the system (I wouldn’t be surprised if there was a secret calibration mode in the RB where you can adjust parameters to make it spot on).
BUY A PROBE THERMOMETER - it’s as essential of the brewing tool as a hydrometer!!!

Phil


#3

I also found my unit gives an off reading of temperature. I believe somewhere in their literature Kegland tells how to adjust the reading up or down as needed if it is off. You could do an boiling/ice water test to see how true the temp reads. Some probes just dont work very well. Phil gives good advice, get a thermometer. Try to get a decent one then check it for accuracy before using.
Cheers,
Teve


#4

I think, before doing that, I will check it’s temp on known temp waters. I got a laser infrared thermometer that I can use as well. I also have a sous vide device, so I can use that to compare temps with just water in there. If I find that it’s just off a certain amt of temp, I’ll just keep that in mind.


#5

I’m not big fan of IR thermometers (w/ laser pointer). I have one but always end up using my probe, I trust it.
The surface emissivity effects the IR reading. Sure, maybe 10% typically, but it could be off by 2x if it hits a surface that’s highly reflective in the IR … or not at all reflective … so you’re back to calibrating your thermometer with a good old K-type thermocouple so you can believe it. You need to trust your measurements, start with a $25 K-type probe, it’ll be a cornerstone in your brewery.

Same is true for my reflectometer. I calibrated it against my hydrometer with various sugar water mixtures. I found that I need to make 3 measurements and throw out the odd ball… not sure why I get an odd ball measurements with the reflectometer, but now I know I get them and I know how to avoid them.


#6

I have the same problem. My boil temp is 110C not 100C and all other temps are out when compared with a probe or standard thermometer. it makes mash temps a bit hard to get correct. a bit disappointing with a brand new robobrew