FoodNet

Foods, their selection and preparation

1935

Page 143

Presented as published in 1935. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Plain ices are prepared from fruit juices and pulp, water, and sugar, and when frozen with rapid stirring have a reasonably smooth tex¬ ture. The texture is improved by the use of a stabilizer like gelatin. A sherbet is an ice to which beaten egg white has been added, or in which milk or cream has replaced all or part of the water. Sherbets have more body and are smoother than w'ater ices. Gelatin also may be used in sherbets. METHODS OF FREEZING In freezing, heat must be absorbed from the mixtures to be frozen. This is accomplished by surrounding them with cold brines. Low- temperature brines are obtained by the melt¬ ing of ice, or the changing of a volatile liquid to a gas. Household methods of freezing are simple and will be discussed first. Household Freezing with Ice. Heat is given off when water changes from a liquid to a solid, or freezes. When the ice melts or changes from a solid to a liquid it must absorb an equal amount of heat. In the home, use is made of melting ice in freezing. Under ordinary conditions, melt¬ ing ice has a temperature of 32° F. By the addition of salt to ice, the rate of melting can be increased and the temperature reduced. The temperatures obtained are in direct pro¬ portion to the weight of salt added to a given weight of ice. Household freezers for making frozen des¬ serts are available in convenient sizes and at various costs. They consist essentially of an outside container, preferably of some non¬ conducting material such as wood, in which the freezing mixture is placed. Into this is fitted another container made of metal, a good conductor of heat, in which the material to be frozen is placed. This is provided with a dasher connected with a handle, so that the mixture can be stirred while freezing. Ice and salt in varying proportions are used to form the freezing mixture. Ice ab¬ sorbs a definite amount of heat for every unit of weight melted. The temperature of the brine formed depends upon the rapidity of the melting. As the proportion of salt to ice is increased, the rate of melting increases and the temperature of the brine is lowered cor¬ respondingly. Mixtures of approximately one part salt to six parts of ice, by weight, A Typical Household Freezer USD. A. U.S.D.A. Equipment for Freezing Special Desserts • Mousses and parfaits are frozen without stirring. These mixtures may be sealed in watertight molds and buried in ice and salt to freeze yield most satisfactory results in freezing ice creams. One part salt to four of ice is pre¬ ferred for ices and sherbet. The cold brine is in contact with the out¬ side of the container in which the mixture to be frozen is placed. If left undisturbed, the mixture will freeze around the sides of the container. The temperature is coldest there, and large crystals will form while the center of the mixture remains unfrozen. For this reason freezers are constructed with dashers to keep the mixture stirred and so promote more even freezing. On one side of the dasher is a sharp-edged knife. As the dasher is turned in the freezer, this knife removes the crystals from the side as fast as they are formed and allows an un¬ frozen portion of the mixture to come in contact with the cold surface. This both decreases the time required for freezing and helps to keep the crystals small.