There are several methods of canning, but the three which are considered the easiest and most popular are: Cooking the fruit in the jars, in boiling water; cooking the fruit in the jars in an oven; and cooking or stewing the fruit before it is put into the jars.
The method most commonly used in this country is the last method, viz., cooking or stewing the fruit before putting it into the jars. This method is not quite as reliable as the first two, as there is a chance of failure, whereas with the first two methods no failure can possibly result provided the cooking or sterilisation has been thoroughly done and air-tight jars used. Another disadvantage of this method is that fruit does not retain its shape nor its flavour so well, this being true especially of the soft, juicy fruits. Therefore it is proposed to deal only with Method No. 1 in this book, and to briefly outline the other two methods.
This method of Canning is done on the same principle as the canning or sterilising of vegetables, the only difference being in the length of time sterilised. Full directions are given further on.
Prepare the fruit as for other methods of canning, and then arrange neatly in jars, which have been washed and scalded with boiling water. Fill the jars with the syrup which has been prepared beforehand, adjust the sterilised rubber rings, and screw on the lids loosely, or, if spring-top jars are used, adjust the wire clamp but do not fasten down. Place the jars in a shallow roasting pan containing two or three inches of water, care being taken to rest the jars on straw, hay, strips of wood, or cloths, then put into a moderate oven, place an inverted pan on top, and allow to cook until the fruit is done, the time allowed depending on the nature of the fruit. Remove the jars from the oven one at a time, screw down the lids tightly, or fasten down the wire clamp of spring-top jars, invert them, then put them in a place out of a draught and cover up warmly so as to cool down gradually. When cool, if screw covers are used, again tighten the lids after the glass has contracted.
Fruit done this way is apt to shrink a little in the jars, and so, if desired, jars can be filled up from an extra bottle.
When doing fruit by the Oven Method, the fruit in the top of the jar is apt to discolour or turn dark, owing to the greater heat, unless an inverted pan is put on the top of the jars.
Two types of Boilers with false bottoms, suitable for Canning or Sterilising Vegetables and Fruits.
After fruit has been prepared by washing, peeling, coring, etc., drop them into the boiling syrup which has been prepared beforehand, and cook the fruit in the syrup until tender. Remove the jars from the boiling water, in which they have been sterilising for 15 to 30 minutes (see Sterilisation), and fill them to overflowing. It is very important that the jars are filled to overflowing, and if there is not sufficient syrup, add boiling water. To prevent air bubbles, slip a spoon or fork into the jar. Wipe the rim of the jar, put on the sterilised rubber ring, and cover and screw down tightly, or, in the case of spring-top jars, fasten down the wire damp. Invert the jars and put them out of a draught. When cold and glass has contracted, again tighten the metal covers.
The work of sealing and filling should be done as rapidly as possible, and the fruit must be boiling hot when put into the jars.
If it is desired to have the syrup very clear, cook the fruit in boiling water, then put into jars and fill up with syrup.