Custards, Blanc-Mange, Jellies, and Creams.
A good rule for custard is five eggs to a quart of milk, and a tablespoonful of sugar to each egg, although a good plain custard can be made with an egg for each cup of milk and four tablespoonfuls of sugar to the quart. Creams and custards that are to be frozen must have at least one-third more sugar than those which are not to undergo this process.
In heating the milk for custard, do not let it quite boil before adding the yolks. My plan, which has proved a safe one thus far, is to take the scalding milk from the fire, and instead of pouring the beaten eggs into it, to put a spoonful or two of the milk to them, beating well all the while, adding more and more milk as I mix, until there is no longer danger of sudden curdling. Then, return all to the fire and boil gently until the mixture is of the right consistency. From ten to fifteen minutes should thicken a quart. Stir constantly. A pinch of soda added in hot weather will prevent the milk from curdling.
Always boil milk and custard in a vessel set within another of boiling water. If you have not a custard or farina kettle, improvise one by setting a tin pail inside of a pot of hot water, taking care it does not float, also that the water is not so deep as to bubble over the top. Custards are better and lighter if the yolks and whites are beaten separately, the latter stirred in at the last.