Notes: fizzy cream soda, butterscotch ribbons, marshmallow whipped cream, rosewood desks and squashy armchairs, a cheerful fire Ensconced in the coziest common room with a big mug of butter beer and a cheerful fire, one can enjoy a whole afternoon just watching snowflakes fall outside the tower window. Butter beer is magic in itself. A decadent concoction of fizzy cream soda and butterscotch, topped with marshmallow whipped cream. No wonder it’s a favorite of wizards worldwide.