Attenuation Issues

[6Trails]

So, all my own fault in the end it's looking like. The opportunity came up in work for some industrial temperature calibrations so I got to check and it turns out my 'calibrated' thermometer I bought was a good way off. I've done the Brewzilla with the adjustments since (only calibrated the high and low between 60 and 76 using this information) and I've seen 84% with LAX and 77% with Hoppin Pils since.

 

[Sadfield]

Wow, it must have been a good way off. Was the brewzilla good to the corrected thermometer, or was that slightly out too, compounding the issue?

 

[6Trails]

Wow, it must have been a good way off. Was the brewzilla good to the corrected thermometer, or was that slightly out too, compounding the issue?

Out in the same direction so it was even more off than I thought. Though in reality only off by the amount the thermometer was (1.8C) as I was compensating the temp on the display to the thermometer.

 

[6Trails]

This reared it's head again of late and I've definitely double checked all temperature monitoring is good, so I've been delving through my past brews to see can I see a trend. Luckily I take notes each brew day right down to equipment changes etc.

I'm really coming to the conclusion now that a combination of equipment and temperature rise near the end of fermentation is stunting the yeast and causing it to finish up early looking back at all my fermentation charts. It could be that I'm ramping too steep (about 2C every 24 hrs) but I've noticed now that it has only ever happened with the combination of the Fermzilla and the Kegland wide heat wrap - maybe this is generating too much heat on the outside of the fermenter before the Pill finally catches up to the target in the middle. Looking back I've not had this happen with the combo of Fermzilla+tube heaters or Stainless+heat wrap.
Will definitely be keeping a closer eye on this going forward anyway, but thought I'd update just in case it helps someone else out.