HI Scott, sorry for delay in response. I'm not sure why the off flavor after pasteurizing. I don't pasteurize mine so can't say. I don't have any off flavors. Some flavor differences come from breed of goat, cleanliness, season, handling, etc. I wish I could help you but I'm not sure. I've heard that low mineral diets can impact goat milk flavor too. maybe someone else will weigh in.