Snape allowed a low chuckle to escape from him and lifted the cauldron from the stand over the burner and moved it to cool on the bench beside the sink. Once they cleaned up the bench and all the chopping boards, knives, and stirring implements, Snape cast a charm around the cauldron to ensure there was no contamination. After they were certain there was no more they could do in the lab, Hermione led the way up the stairs to the sitting room, where she stoked the fire.