We kegged our beer after fermentation, the gravity went from 1.048 to 1.012so we thought most of the fermentation was finished. We put in the fridge to carbonate. Tasted good but somewhat yeasty. Now 4-5 days later has sulfer smell and slight taste. Is this ok and will it go away. We thought it could condition in keg in refrigerator while carbonating. Should we take it out and let it condition at room temp? Should we vent Co2 off? We used Wyeast 3944 which we were told is slow, but we let it primary for almost 2 weeks.