In my early days Ive come across a few hot alcohol brews. Never could figure out what exactly was causing it. I wasnt fermenting too warm, which was the obvious answer.
I looked at my process and changed some things and havent had an issue since. Not sure if any one of these was the culprit or maybe a combination of both.
I started rehydrating dry yeast before pitching. I know what the instructions on the package says, but seems rehydrating gently with water is better than being thrown head first into a sugary wort. Think of it as the difference of being gently woken up by the rising sun and chirping birds vs being thrown out of bed at Odark thirty by a screaming drill instructor banging on a metal garbage can.
I used to always get impatient when cooling wort and pitch the yeast a little too warm. Used to rationalize that by pitching the yeast and topping up with cool water it should all be good
.or be good shortly after. No, after I started using my temp control fridge and seeing that actual live temp of the wort broadcast brightly in red LEDs, I realized it takes a long time for the wort to cool ambiently. In that time, who knows what that yeast was doing. I dont do that now and just suck it up no matter how long it takes to drop those last few degrees.