The success of preserving and canning depends upon heating the fruit until all germs are destroyed, then sealing it air-tight while still scalding hot. In this way no new germs of ferment or mold can reach the fruit. Patent jars are generally used, and must be put into scalding water before being filled to prevent their breaking, and also to sterilize them. The preserve must be put into them scalding hot, a spoon-handle run down the sides to liberate any bubbles of air, the jar filled to the very brim, and the top put on each one at once after it is filled. A simple and very effectual way of hermetically sealing fruit is to cover it with paraffin. This can be obtained at any pharmacy. Place the paraffin in a small saucepan on the side of the range; it melts at a low degree of heat. When the jar or glass is filled with hot preserves wipe the glass close to the fruit to free it of syrup. Cover the top with a tablespoonful of liquid paraffin, and do not move the jar until the paraffin has set; it will then adhere closely to the glass. This will be found a very easy and satisfactory way of sealing fruits. The paraffin when taken off the fruit can be washed and kept to use again. In preserving, sugar is used in the proportion of three quarters of a pound or one pound of sugar to a pound of fruit, and the fruit is thoroughly cooked. In canning, one quarter of a pound of sugar to a pound of fruit is used, the fruit is only thoroughly scalded, and so retains its flavor better. Fruits should be under rather than overripe for preserving, and only the finest should be selected. Inferior fruit may be used for jams. It is most abundant when at its best, and at this time it is cheapest. A porcelain-lined kettle and wooden spoons should be used in the cooking, and a wide-mouthed funnel is a convenience for filling the jars.
The skin can easily be removed from peaches, leaving a smooth surface, by placing them in a wire basket and plunging it for a moment into boiling lye. The lye is made by adding two cupfuls of wood ashes to four quarts of water. From the lye put the fruit into cold water and rinse it several times, then rub off the skin. Cut each peach in two and place again in cold water to preserve the color until ready to use. Place in a porcelain-lined kettle three quarters the weight of sugar you have of fruit. Add a very little water to dissolve the sugar. Let it boil a minute, and take off any scum that rises. Then add as much fruit as will float without crowding, and cook until it is transparent, but not until it loses shape. Remove each piece separately as soon as it is cooked. When ready to fill the jars place them carefully in a pan of boiling water; have the tops and rubbers also in hot water. Part of the fruit has become cooled while the rest was cooking, but, as it must go into the jars hot, place it again in the boiling syrup, a little at a time. Use a ladle or cup to dip out the fruit; run a spoon-handle around the inside of the jars after they are filled to liberate any air bubbles. Add enough syrup to fill them to overflowing, and adjust the rubber and top on each jar as it is filled. Any juice that is left over may be boiled down to a jelly, or it may be bottled to use as flavoring or for sauces.