Experimental cookery

The temperatures given previously and those reported by Williams are for soft custards. Baked custards may be cooked several degrees higher than soft custards without curdling. This lower curdling temperature for soft custards is probably due to the stirring, which increases the tendency for separation of the custards into curds. Hence, it is important in making soft custards to prevent heating after a certain temperature has been reached. This can be accomplished by putting the cooking pan in cold water or by pouring the custard into another utensil. Between the temperature at which coagulation starts and the curdling point is a temperature at which the custard has the best texture and flavor for serving. Williams has reported that the optimum temperature for custards made of 1 egg, 1 cup of milk, and 1 tablespoon of sugar is 82.5°C, When 2 yolks are substituted for the whole egg the optimum temperature is 83.5°, and when 2 whites are substituted for the whole egg the optimum tem- perature is 82°. Custard pie. In cooking custard pie one of the major difficulties is to prevent soaking of the crust. Increasing the proportion of egg helps, as the custard then coagulates at a lower temperature. Thus 1^ eggs to a cup of milk is better than 1 egg. Prewarming the milk before adding it to the other ingredients shortens the time before coagulation takes place. One way to prevent soaking of the crust is to cook the pastry and the 346 EGG COOKERY filling separately. Bake the pastry on the bottom side of a pie pan with sloping sides. Bake the custard in a pie pan of the same size as the one used for the crust, setting the pan in hot water and using as low an oven temperature as desired. After baking the custard, cool it until the pan feels warm but not hot to the hand. At this temperature it has set sufficiently to hold together, yet will not break so easily as when cold. Run a knife or spatula around the edge of the custard and, tilting it at about a 45-degree angle, shake and slide it out of the pan into the crust. Whipping Eggs and Egg Whites When an egg is whipped with an egg beater, or similar utensil, its vol- ume increases, owing to incorporation of air. The egg white because of its low surface tension and the stability of its surface films readily forms a foam. The essentials for a stable foam have been discussed in Chapter I. They are a low surface tension, a low vapor pressure, and a tendency for the substance in the surface to solidify, hence giving rigidity and permanence. Stages o£ stiffness in beating egg whites. With slight whipping the incorporated air bubbles are large, the egg white appears foamy yet transparent, is very runny, and will flow readily. With longer beating the air cells in the egg white become smaller, the appearance of the egg white is less transparent and more white. It still flows if the bowl is partially inverted. The egg white becomes stiffer with continued beating. The stiff- ness is due, in part at least, to the finer division of the air bubbles, and thus the amount of egg white utilized in forming films is greater. Many small air bubbles with their fine cell walls may be stronger and more rigid than a few large cells. As beating is continued the egg becomes very white, begins to lose a little of the moist, shiny appearance, and is stiff and rigid.