Pule donkey cheese is the most expensive cheese in the world. Produced by only one farm in the world, pule will cost you about $600 for a single pound. Making it requires more time and effort than most other cheeses. You need over 6.5 gallons of donkey's milk just to make one kilogram of cheese. That's 2.5 times more than what you need to make mozzarella. So how does pule compare to other types of cheese? And why is it so expensive?