Poor beer quality with conical fermenter

I purchased a 14 gal SsBrewtech Chronical fermenter about a year ago and every beer I have made since has not come out well. My previous beers, which I fermented in 6 gallon glass carboys, were coming out better and better. Once I introduced the Chronical, however, my beer has off tastes, somewhat sweet. I have two theories for it:

1) I'm only brewing 5 gallon batches and the additional headspace in the 14 gal Chronical may be affecting the flavor.

2) I'm still temperature controlling with a Son of a Fermentation Chiller, which may be misguiding me on the actual temperature of the wort since the temperature gauge is in the air inside the fermenter and not the wort. So perhaps I'm fermenting at higher temperatures.

Has anyone else experienced this? Any suggestions? I want my great homebrew back but want to keep using my new toy! Thanks.

 

I’ve never used a chronical before, but that really stands out to me as a potential culprit. Your wort can be several degrees higher than the headspace, and I think it would cause issues for your controller to maintain steady temperatures.

 

You're only controlling the ambient air temperature and while you might be doing a good job of that, the beer is doing a wild ferment with much higher temperatures. Tape the gauge to the side of the conical low enough to be measuring where the beer is. Put something over the gauge to keep it from getting confused with the air temp. Bubble wrap might be a good choice.