Iy hope the group can help figure this out because I am having problems. I have been brewing for over 4 years. I started with extracts then to partial mash and finally to BIAB. At last count I have done 69 batches of beer with no problems until recently. Out of my last 7, five gallon brews 4 have been bad. The beers have had a very strong off flavor and smell that I have a hard time describing. It is not the hop, banana, cloves type off. It is more medicinal, alcohol. Also, the body of the beer is very thin. The beers I have brewed that have gone bad have all been darker beers, one porter two milds and a moose drool clone with a variety of yeasts (Nottingham, Safale 05, Mangrove Jacks west coast ale.). I have brewed enough successful beers to know what a green beer is like and this is not it. I have also kegged these beers and the taste and flavor do not go away. One puzzling thing is that these bad brews have not all been in a row. I have also brewe I have brewed a successful brown and a cream ale in between the bad ones, but the last three have been bad. I have also brewed three 2 1/2 gallon batches where the only thing different is the brew pot (and aluminum 7 gallon pot). I brew with a 62 quart stainless steel brew pot ans a camp stove burner. Clean using the same method I have always used, wash with unscented hand soap, then oxiclean, rinse and starsan right before using. I have transfered the cold wort using the pot ball lock with a hose, tried different hoses, and last time transfered with a new 1/2" siphon with a new hose. I have fermented in plastic buckets that have been used several times, a big mouth carboy that has been used three times and the last beer in a brand new large mouth carboy. I brew in my garage with the door open and know there are some pollens in the air. I do not have a fermentation box and ferment beer in my house where temperatures have mostly been around 77 but last brew was at 74. I think this pretty well covers it. If there is additional info needed, let me know. Any help you can give would be greatly appreciated. Ihave never checked pH but I am on well water so chlorine is not an issue. I have never checked pH but know my well water runs a little high.