Once he had the burner set up beneath the cauldron, he lit the flame and removed the stasis spell once the temperature was correct. Within an hour, the potion was bubbling away happily, and Snape was chopping and slicing up his ingredients in preparation to add them. When it was finally time, he took up a glass stirring rod and placed it in the cauldron, followed by all of the ingredients in order, stirring occasionally to prevent the brew from turning into a lumpy mess, which would effectively render it useless.