I used Wyeast's Pacman strain to make an IPA with an all grain recipe. OG: 1.064 FG 1.016. Tasted real fine before I pitched yeast, but after 1 and half weeks in the fermenter at 62-64 degrees F it turned out with an overpowering diacetyl taste. I'm puzzeled because Wyeast says this strain does not produce any to little diacetyl. I'm going to bring the temp up to mid to upper 60s and hope the residual yeast wipe out the butter flavor. Has anyone else encountered this problem with Pacman?