Originally Posted by jigidyjim
Oh, I didn't realize that diacetyl was always an off flavor - I thought it was a property that some yeasts had. Guess I need to read more about it.
Oh, no, it's not always an off-flavor! I think it's perfectly acceptable in some beer styles, particularly some English styles. I've heard that ringwood yeast is a notorious diacetyl producer, but I've never used that strain.
In lagers and some other styles, it's considered an "off" flavor, though.