Diacetyl-infection or overtemp?

[UncleByron]

I'm trying to figure out if my beer is infected or not. I'll try to keep this short.

I brewed a batch of beer last Wednesday. By Saturday, the airlock had stopped bubbling. I took a gravity reading on Monday, it wasn't quite as low as I had hoped, and I tasted a hint of what I think is diacetyl. On Wednesday I took another reading (same gravity as Monday) and the off flavor was overwhelming. I've read on here that if the diacetyl flavor gets worse after primary fermentation is complete, the beer is likely infected. However, I pretty much botched this batch. I had to pitch the yeast at 85 F so that I could leave for work, AND the thermostat in my spare room wasn't working so my fermentation was over temp for the first 48 hours... When I first realized it I saw my fermometer at 77 an my heart dropped (just got the parts to convert my spare fridge into a fermentation chamber in the mail yesterday).

So I have two questions...#1 is infection or overtemp the likely cause of my off flavor? #2 is there any hope of salvaging this beer? I've read that if the cause was overtemp, pitching a new yeast starter in the secondary can clear it up.

 

[Brewtah]

How long has the gravity been stable? What was OG and what is gravity now? Does it taste like a cleaning product/alcohol, butterscotch or more acidic like vinegar? What yeast did you use?

 

[Jeffinn]

At those fermentation temps its likely that theres some fusel alcohols in your beer. If thats the case, aging probably won't help but at this point you have nothing to lose so let it sit for a week or two and see if it helps.

 

[fastengine]

Diacetyl is a byproduct, not really an infection.
What yeast and what recipe?
How was your sanitation?
Yeast like Nottingham tastes very bad at warmer ferment temps.

 

[UncleByron]

OG was 1.049, gravity has been 1.018 since at least Monday. Tastes a little like butterscotch and a lot like I have no idea what (not pleasant though). Doesn't taste like cleaning product, acid, vinegar, or alcohol, it isn't sour. Used WLP005. Recipe was a bitter. Somewhere around 84% MO 3% biscuit, 8% crystal, 5% brown sugar