Science in the Kitchen / A Scientific Treatise On Food Substances and Their Dietetic Properties, Together with a Practical Explanation of the Principles of Healthful Cookery, and a Large Number of Original, Palatable, and Wholesome Recipes

by E. E. Kellogg

Cook the fruit slowly in a porcelain-lined or granite-ware kettle, using as little water as possible. It is better to cook only small quantities at a time in one kettle. Steaming in the cans is preferable to stewing, where the fruit is at all soft. To do this, carefully fill the cans with fresh fruit, packing it quite closely, if the fruit is large, and set the cans in a boiler partly filled with cold water, with something underneath them to prevent breaking,—muffin rings, straw, or thick cloth, or anything to keep them from resting on the bottom of the boiler (a rack made by nailing together strips of lath is very convenient); screw the covers on the cans so the water cannot boil into them, but not so tightly as to prevent the escape of steam; heat the water to boiling, and steam the fruit until tender. Peaches, pears, crab apples, etc., to be canned with a syrup, may be advantageously cooked by placing on a napkin dropped into the boiling syrup.

Fruit for canning should be so thoroughly cooked that every portion of it will have been subjected to a sufficient degree of heat to destroy all germs within the fruit, but overcooking should be avoided. The length of time required for cooking fruits for canning, varies with the kind and quality of fruit and the manner of cooking. Fruit is more frequently spoiled by being cooked an insufficient length of time, than by overcooking. Prolonged cooking at a boiling temperature is necessary for the destruction of certain kinds of germs capable of inducing fermentation. Fifteen minutes may be considered as the shortest time for which even the most delicate fruits should be subjected to the temperature of boiling water, and thirty minutes will be required by most fruits. Fruits which are not perfectly fresh, or which have been shipped some distance, should be cooked not less than thirty minutes. The boiling should be very slow, however, as hard, rapid boiling will break up the fruit, and much of its fine flavor will be lost in the steam.

Cooking the sugar with the fruit at the time of canning, is not to be recommended from an economical standpoint; but fruit thus prepared is more likely to keep well than when cooked without sugar; not, however, because of the preservative influence of the sugar, which is too small in amount to prevent the action of germs, as in the case of preserves, but because the addition of sugar to the water or fruit juice increases its specific gravity, and thus raises the boiling point. From experiments made, I have found that the temperature of the fruit is ordinarily raised about 5° by the addition of the amount of sugar needed for sweetening sub-acid fruit. By the aid of this additional degree of heat, the germs are more certainly destroyed, and the sterilization of the fruit will be accomplished in a shorter time.

Another advantage gained in cooking sugar with the fruit at the time of canning, is that the fruit may be cooked for a longer time without destroying its form, as the sugar abstracts the juice of the fruit, and thus slightly hardens it and prevents its falling in pieces.

The temperature to which the fruit is subjected may also be increased by the same method as that elsewhere described for sterilizing milk, the covers of the cans being screwed down tightly before they are placed in the sterilizer, or as soon as the boiling point is approached, so that the steam issues freely from the can. See [page 396]. If this method is employed, it must be remembered that the cans should not be removed from the sterilizer until after they have become cold, or nearly so, by being allowed to stand over night.

Use the best sugar, two tablespoonfuls to a quart of fruit is sufficient for most sub-acid fruits, as berries and peaches; plums, cherries, strawberries, and currants require from five to eight tablespoonfuls of sugar to a quart. Have the sugar hot, by spreading it on tins and heating in the oven, stirring occasionally. See that; it does not scorch. Add it when the fruit is boiling. Pears, peaches, apples, etc., which contain a much smaller quantity of juice than do berries, may be canned in a syrup prepared by dissolving a cup of sugar in two or three cups of water. Perfect fruit, properly canned, will keep without sugar, and the natural 'flavor of the fruit is more perfectly retained when the sugar is left out, adding the necessary amount when opened for use.

If the fruit is to be cooked previous to being put in the cans, the cans should be heated before the introduction of the fruit, which should be put in at a boiling temperature. Various methods are employed for this purpose. Some wrap the can in a towel wrung out of hot water, keeping a silver spoon inside while it is being filled; others employ dry heat by keeping the cans in a moderately hot oven while the fruit is cooking.

Another and surer way is to fill a large dishpan nearly full of scalding (not boiling) water, then gradually introduce each can, previously baked, into the water, dip it full of water, and set it right side up in the pan. Repeat the process with other cans until four or five are ready. Put the covers likewise into boiling water. Have in readiness for use a granite-ware funnel and dipper, also in boiling water; a cloth for wiping the outside of the cans, a silver fork or spoon, a dish for emptyings, and a broad shallow pan on one side of the range, half filled with boiling water, in which to set the cans while being filled. When everything is in readiness, the fruit properly cooked, and at a boiling temperature, turn one of the cans down in the water, roll it over once or twice, empty it, and set in the shallow pan of hot water; adjust the funnel, and then place first in the can a quantity of juice, so that when the fruit is put in, no vacant places will be left for air, which is sometimes quite troublesome if this precaution is not taken; then add the fruit. If any bubbles of air chance to be left, work them out with a fork or spoon handle, which first dip in boiling water, and then quickly introduce down the sides of the jar and through the fruit in such a way that not a bubble will remain. Fill the can to overflowing, remembering that any vacuum invites the air to enter; use boiling water or syrup when there is not enough juice. Skim all froth from the fruit, adding more juice if necessary; wipe the juice from the top of the can, adjust the rubber, put on the top, and screw it down as quickly as possible. If the fruit is cooked in the cans, as soon as it is sufficiently heated, fill the can completely full with boiling juice, syrup, or water; run the handle of a silver spoon around the inside of the can, to make sure the juice entirely surrounds every portion of fruit, and that no spaces for air remain, put on the rubbers, wipe off all juice, and seal quickly.