In 1/3 of the milk is diluted starch, carefully and constantly confused. The remaining milk to the boil on the fire with sugar. Yolks are broken well and them in a thin stream and at constant stirring add the milk, starch and coffee. To the mixture, after cooling, added egg whites broken down into hard snow. Soufflé is poured into the form and bake in a moderate oven. Serve hot, sprinkled with powdered sugar optional.