Diacetyl - From which mistake?

[GreenDragon13]

Made an IPA and wound up with a touch of Diacetyl. Not to the point of being ruined, I drink it and my friends said it was good, but not something I would be proud of at the HB club meeting.

I had it fermenting and temps were 67-ish (safale US 05). I lost track of the weather and came out of work to find it was almost 90F. Got home and it was 82F in the room. I carted it into air conditioned room and forgot to turn the temp down, so another day at 78. So at day 9 I racked into corny keg and started the cold crash (7 days).

Do you think the off flavor (Diacetyl?) was from the too warm temps or cold crashing too soon?
I have since got a mini fridge (free! WooHoo!) and an STC-1000 temp controler so I won't have to deal with this next batch.

 

[Rob2010SS]

Stupid question, but you sure it's diacetyl? Describe it a bit if you could. I've never run into diacetyl myself, but I know on lagers, you need to have a diacetyl rest as fermentation is finishing up. This is done by raising the temperature to the 65*F - 68*F mark.

Reason I ask why you think it's diacetyl is that you kind of did this, to the extreme though. It did warm up quite a bit. Which leads me to ask perhaps it's an off flavor from the yeast due to the high temp?

Also, you racked to keg at day 9. Perhaps that was too soon?

 

[friarsmith]

Without additional details on the flavor, my guess is you're tasting one of two things:

*Esters (think the weird sweetness of Juicy Fruit gum) from the warm fermenation

*Possibly fusel alcohol (nail polish remover or paint thinner or hair spray), but I wouldn't suspect this unless your beer rose above 80* w/ US-05 for a day or more.

If you're tasting butterscotch, buttery movie popcorn flavor, etc combined with a slick/greasy feel on the palate, that's a dead ringer for diacetyl. I usually wait until day 14-18 or so for an IPA before racking to a keg to give the yeast time to clean up the diacetyl. Perhaps the temperature difficulties, yeast stress, and racking at day 9 may have not given the yeast time to clean up the beer.

Drink it really cold with an orange or lemon slice and that will cover up many a flaw !