I use Fage yogurt, either 2% OR 0%, as starter every week. I've never had a problem with it. Make sure there wasn't any hidden grease/oil on you pan or cooking utensils. During the hot weather, I can't let my yogurt go the 10 to 12 hours like when it is cooler. It seems to get chunky and very, very thick. Still tastes good, but don't like it like ricotta. I change my Fage starter about every third batch, because I want fresh cultures, and I can't keep my DH from eating the last 1/2 c. I was dumping the whey and found out that if I mixed in back in that my mix was smoother. I was using the whey in my bread.