My last few batches have had a low conversion efficiency compared to normal, and the wort runoff has been kinda cloudy. My brewhouse efficiency has also been a bit low. But on all of those brews, I’ve been doing multiple things at once and hadn’t taken the time to look for an answer. Today, doing the first of 2 test brews, I figured I’d check calibration on things. Turns out my brewing thermo read 15F lower than my calibration thermo! Recalibrated the brewing thermo and I’m back up to 97% conversion efficiency and the mash runoff was crystal clear, like it should be. DOH!
Denny, what do you use for a calibration thermometer?
Denny, any idea what caused your brewing thermometer to get out of whack? What kind of thermometer?
I have both an alcohol immersion thermo and a VWR NIST certified “lollipop”. I used the lollipop today, but if I want to be dead accurate I break out the immersion.
It’s a bimetal dial thermo that I’ve had since I started brewing 18+ years ago. Came with my original equipment. Since it’s made to be adjusted, sometimes the adjustment slips. But I also dropped it a while back and hadn’t checked it since then Normally I check it every few brews, but things have been so crazy the last few times I brewed I hadn’t gotten to it. Another lesson…if yer gonna brew, then BREW! Don’t try to write a book and answer email at the same time!
Thanks.
I had the same thing happen on my HLT thermometer. I had been doing cold sparges before Marshall made it cool. It was 50 degrees off. I keep it out in the garage and I think the temperature swings over 15 years messed with it. I calibrated it to my Thermopen.
I don’t like those dial-face thermometers. I use to use one when I first started brewing and would always be a few degrees off every few brews. It seemed like even the slightest bump of it would mess up the calibration. Ever since I bought a Thermapen, I have been completely pleased with the purchase in both speed and accuracy. Also good to have one to calibrate other thermometers to as well.