PRINCIPLES OF PRESERVING
49. PRESERVING consists in preparing fruits in perfect condition to resist decomposition or change by cooking them in heavy sirup. The cooking is done so slightly that the original form, flavor, and color of the fruit are retained as far as possible. This process is similar to that of canning by the open-kettle method; that is, the fruit and sugar are combined and cooked to the proper consistency in the preserving kettle. Sugar is used in such quantity in the preparation of preserves that it acts as a preservative and prevents bacteria from attacking the foods in which it is used. If preserves of any kind ferment, it may be known that not enough sugar was used in their preparation. The sterilization of the product and the air-tight sealing of the containers, which are necessary in the canning of fruits and vegetables, need not be resorted to in the case of preserves.
50. SELECTION OF FRUIT.--When fruit is to be made into preserves, much attention should be paid to its selection, for, as a rule, only the finest fruits are used for preserving. This is especially true of the smaller fruits, such as berries and cherries, for they are preserved whole. Therefore, in order that they may have a good appearance when preserved, it is necessary that they be as perfect as possible to begin with. In addition, the fruit should be thoroughly ripe, but not mushy nor overripe. As the cooking of the fruits in sirup hardens them to a certain extent, fruits that are not sufficiently ripe cannot be used, for they would be too hard when done. If care is used in selecting fruits that are to be preserved, a good-appearing product will be the result, since this process is carried on in such a way as not to impair their shape.
51. METHODS OF PRESERVING.--Several methods of preserving fruit are in practice, but in general the same principles characterise each one. Probably the most successful method consists in bringing a certain proportion of sugar and water to the boiling point, dropping the fruit into the sirup thus formed, and cooking it for a definite length of time. Boiling fruits in heavy sirup has a tendency to make them firm and solid, rather than to cook them to pieces, as would be the case with water or a thin sirup. Even very soft berries, when used for preserves, will retain almost their original size and shape if they are properly cooked. Except for the fact that a heavier sirup is used, the process of preserving fruit is exactly like that of canning fruit by the open-kettle method. The chief precaution to take in this method is that as little water as possible be used, so that the sirup may be very thick when the fruit is added.
Another method that may be recommended because it helps to keep the fruit in good condition consists in cooking it in its own juice. In this method, equal quantities of fruit and sugar are put together and allowed to stand until enough juice is formed, preferably overnight, so that the fruit may be cooked without the addition of any water. Strawberries are excellent when preserved in this way.
Whichever method is followed, better results will be obtained if only a few quarts of fruit are cooked at a time. When a large quantity of berries, for instance, is added to the boiling sirup, they will form such a thick layer that they will have to remain over the fire a long time before they come to the boiling point. They will therefore be much more likely to crush and give the finished product a mushy appearance than if a smaller quantity, which will form a thinner layer, is cooked each time.
52. UTENSILS FOR PRESERVING.--The equipment necessary in the making of preserves is similar to that used for making jelly, with the exception of the dripping bag and the hydrometer. A good-sized preserving kettle is, of course, required for the cooking of the fruit and sirup; a measuring cup and a quart measure are needed for the measuring of the ingredients; and a long-handled wooden spoon or paddle is the most convenient utensil with which to stir all foods of this class. Containers similar to those used for jelly will be satisfactory receptacles in which to put preserves, but as preserved fruits are not turned out in a mold, almost any kind of wide-mouthed bottle or jar may be used for this purpose. Paraffin should also be provided, as this should always be used for the first covering to prevent the formation of molds, which are likely to grow on moist sweet substances exposed to the air. Before using paraffin for preserves, they should be allowed to stand until the surface has become absolutely dry. It is well to label preserves, too; so labels should be kept on hand for this purpose.