Much of the drudgery attached to fruit canning, as well as the thrifty housewife's fear that things "won't keep," has been eliminated through a better understanding of sterilization, and the advent of the modern, self-sealing jars.
According to this method the fruit, water, and sugar are boiled together until fruit is tender, then sealed. If fruit is very rich in juice, as raspberries, strawberries, or cherries, very little water is needed; in fact, some housewives sugar the berries an hour before boiling. This will draw enough juice to cook without burning. If quantity rather than quality is desired, add enough water barely to cover bottom of kettle before putting in the fruit and sugar. The success of canning is not as dependent on certain proportions as is preserving or jelly making. The only possibility of spoiling the fruit is from lack of cleanliness or not having all ingredients thoroughly heated while filling and sealing. When fruit is tender, skim off any foam that may rise to top, have the sterilized jars set in a pan of hot water, have the tops convenient in a pan of boiling water; now set the wide funnel in neck of jar, and with a ladle distribute fruit and juice evenly, filling brimful; then wipe off jar quickly to remove seeds or fruit pulp, clamp on top as each jar is filled, and set aside on a thick cloth or rack to cool; When cold, try each top to see if it is on tight, then wipe carefully and place in cool, dry place.
As a general rule, allow two cups of water to one of sugar for the canning sirup. Boil the sirup for ten minutes, counting from the time it begins to boil; skim off any scum that rises. Prepare the fruit as desired or needed, pack closely in sterilized glass jars, fill with the sirup, and place the jar covers on lightly. Have ready a large flat kettle-a wash boiler is best. Place in the kettle a false bottom of slats, or a packing of clean hay or excelsior, taking care that the surface is kept even. On this place the jars so they will not touch each other. Fill with warm water almost to the necks of jars, cover kettle, and bring to boiling point. Add hot water from time to time, to keep it up to the neck of the jars. For small fruits cook twenty minutes; large or firm fruit will require a little longer, while in high altitudes it will be found necessary to extend the time still farther for both small and large fruit. Remove jars while boiling hot, and set aside to cool. Do not place on a cold or wet surface or in a draft. Before putting away, test the covers to see that all are tight.
According to one's taste or to the acidity of fruit the proportions of sugar or water may vary. Fruit that is to be used for baking should be packed very close, that less water may be required, but the sirup must be very sweet.
To can unripe fruits for baking purposes or to cook into sauce during the winter, the following method is recommended:
Use unripe grapes, gooseberries, or rhubarb, cutting the latter into small bits. Pack the fruit into sterilized jars, keeping a silver knife or fork in the jar, then fill with cold water. To prevent the formation of air bubbles, turn the knife occasionally. When brimful, remove the knife and clamp on the cover.