This formula makes 100 lb or 50 qt of milk. Put cold water in a steamjacketed kettle, add powdered milk, and beat with a wire hand whip until the milk powder is dissolved. (Milk powder will not dissolve in hot water.) When the milk powder is dissolved, add the butter in small pieces. Heat the mixture to 145'F, apply heat. In taking the temperature of liquids, be sure to stir the mixture thoroughly from the bottom up, as the temperature at the bottom may be 5 to 10' higher than at the top. If a steam kettle is not available, make a satisfactory double boiler by placing a smaller vessel inside of a large vessel filled with water. If direct heat is used, the flame should be very low and the mixture should be stirred constantly in order to prevent scorching. Cool immediately by placing the cans of milk into a water bath until the temperature is reduced to 50'F, stirring the milk occasionally to aid the cooling.