The Souffle Dish
A souffle dish is a straight-sided baking dish made of ovenproof glass or pottery. Size is important, as the batter should fill the dish at least three-fourths full to allow the souffle to rise without falling over the edge.
The Mixing Bowl
Always use a glass or metal bowl and clean beaters to beat the egg whites. Plastic bowls may contain a greasy film or residue on them that will reduce the stability of the egg white foam.
How to Bake Souffles
Never open the oven door while the souffle is baking unless you think it is done.