Milk smells delicious and sweet before heating but after heating over 165 degrees f and after cooling it has a sulphur or rotten egg smell. The hotter the milk is heated the stronger the smell. I've dreamed of making my own yogurt and cheeses for years and now that I'm finally doing it I'm encountering this problem. but so far everything that I try to make that requires the milk to be heated ends in stinky sulphur smelling yogurt or cheese. I've scoured the internet for info on this and haven't found anything. It's not a "goaty", "musty" or cooked smell. It's not "salty" or "bitter" or "sour". In fact, the taste of the milk isn't as bad as the smell. Has anyone dealt with this before when cheesemaking or pasteurizing? Any input would be greatly appreciated!