I’ve been convinced for years that temps at or even below the manufacturer’s stated temperature range produce better beer - for my taste buds.
The last two beers I brewed have supported that conviction. I unplugged my ferm fridge to clean and air it. Then I brewed a Moctoberfest with US-05. Did a Hochurz mash (142F for an hour, 158F for 30 minutes - others have different definitions of Hockhurz). Boiled for about an hour, chilled to 45F, ozygenated, pitched my rehydrated US-05, and placed the beer in my ferm fridge with the thermostat set to 58.
I have developed great faith in yeast. They do what they’re intended to do. So, I don’t open the fridge to check for fermentation. They always ferment. About five days later I turned the thermostat up to 62F and dreamed of a smooth, tasty beer. About five days later I turned the thermostat up to 65F. About five days later I opened the fridge to take a gravity reading. The bucket felt warm. The Fermometer was not showing any reading. How could that be? I had left the fridge unplugged in a room that was often 80F during the day!
I plugged in the fridge and set the thermostat to 40F. About five days later I kegged my nice clear beer and put it in my keezer at 37F. Once it was cooled and carbed, It tasted … harsh, slightly sour, not so great.
I immediately brewed another batch identical to the previous one and fermented it with the same profile, but with the fridge plugged in! It’s excellent. Not as smooth as a lager version of the same beer, but quicker.
After a couple of months, the hot-fermented beer is still harsh and the cool-fermented beer is excellent.