Looking for some thoughts and ideas here. I built out my HERMS system and on my second brew with it, I brewed an amazing Mexican Lager using flaked maize for the first time and a multi-step mash and a much shorter brew day than I thought. Its being carbonated right now, but already tastes freaking amazing. Hearing this, one would think that all is well in the land of beer and brewing over here, but I am dealing with an issue that I'd rather not deal with.
I'm using a Ranco controller (single stage) to measure and control the pump that recirculates the mash through the heat exchanger. What I 've found is that the Ranco Controller measures the temperature about 8 degrees too low (in other words, it wants to push my mash temp way too high). I've used three different calibrated thermometers to check against what the Ranco is telling me, and the thermometers agree while the Ranco is the outlier. Additionally, my other Ranco (which controls the burner under the HLT) measures the temperature identically to the first Ranco.
When brewing the Mexican Lager I programmed all of my temps 8 degrees lower than target and based upon my analog thermometers I hit my temps throughout the mash schedule.
I've google searched hoping to find a way to calibrate the Ranco, but its specifically stated that they cannot be calibrated. Do I have to live with this and continue to set my temps low, or is there something I can do to get these controllers properly calibrated?
The other thing that has me thinking is regarding the quality of the Ranco controllers as a whole. I'm using them to control both of my fermentation freezers and while I turn out beer that I generally love, I'm getting concerned that the data I am collecting is garbage because the controllers aren't properly reporting/controlling the temp.
Anyone experience this? Any thoughts on how to fix the issue, or do I have to live with it?
~widget