The trick to fondue is to melt it and combine without separating the fat from the curd. If it gets too hot it can scorch on the bottom, creating a burnt flavor. Or, it can separate into fats and solids. That is not a nice experience. It's best to use a whisk during the melting phase to keep it smooth.
Keyword 3 cheese, Adaptable, Cheese and wine, Cheeses, Fondue, Kirsch, liqueur, Swiss