Hot alcohol taste got stronger with time

I made two gallons of Mr. Beer oatmeal stout in some one gallon jugs with airlocks. At bottling time it tasted a little like hot alcohol so I decided to wait it out. Two months went by and the flavor has gotten stronger to the point of not being drinkable.

I did use white sugar to prime but have done this before and not gotten an off flavor. It did motivate me to move to dextrose just in case.

It was my understanding that hot alcohol flavors come with high brewing temps. Since these fermented in 1 gallon jars, and fermented at the same time I was doing some 6 gallon brews in the same room that came out fine, I am not sure what I did wrong.

I would like to know for next time.

Could be fusel alcohol what temp did you ferment at? Watch out for high fermentation temps early on that could cause the hot taste. Also look out for bad hangovers with fuels.

I started controlling fermentation temps by placing my fermentor in a ice chest with frozen water bottles. Search for swamp cooler on this site you'll get great examples to follow.