To be successful in jelly-making it is necessary to understand a few of the simple underlying principles. The making of jelly is possible through the presence in the fruit of pectin, a carbohydrate, somewhat similar in its properties to starch. This element exists in largest quantities in the following fruits: currant, apple, quince, grape, blackberry and raspberry; so that these fruits are preferred for jelly-making. Moreover, the pectin is at its best when the fruit is just ripe or a little under-ripe. Last, it must be remembered that if the juice ferments or if the cooking of the jelly is continued too long, the pectin undergoes a change and loses its power of gelatinizing.

After insuring the presence of the pectin, the matter of next importance is to add the right quantity of sugar. The rule is to measure the juice and add an equal amount of sugar; but the rule must be followed with discretion. If the fruit contains an unusual percentage of sugar, less sugar should be added; if it is less sweet than usual, more should be added to make up the deficiency. The sugar will dissolve more quickly if first heated in a moderate oven, and will then in no way interfere with the cooking.

Jelly should be put into glasses that have been thoroughly sterilized and covered according to the directions given under "Preserving Fruit." It should, however, stand twenty-four hours before being covered. If possible lay a sheet of glass over the tumblers and stand them in a sunny window.

Apple Jelly

Wash the apples; remove stem and blossom ends and cut into quarters. Put them in a preserving kettle, adding enough cold water to come nearly to the top of the apples. Cover and cook gently until the apples are soft and clear. Mash the apples and drain them through a sieve in which two thicknesses of cheesecloth have been laid or through a jelly bag. Avoid squeezing the bag or the jelly will be clouded. Boil twenty minutes and add the heated sugar, allowing two cups or one pound to every pint of juice. Boil five minutes; skim, and test by putting a teaspoon of juice in a cool saucer. If it jellies at once, remove from the fire and pour into sterilized glasses.

Quince Jelly

Follow the recipe for Apple Jelly, using part apples if desired, and saving the better parts of the fruit for canning.

Mint Jelly

Follow the recipe for Apple Jelly, adding oil of peppermint to flavor.

Currant Jelly

Wash and pick the currants, but do not remove the stems. Put them in the preserving kettle, crushing a few in the bottom first; heat slowly, stirring frequently. When the currants are hot, mash them with a potato masher and let them drip the same as the apples for apple jelly. After this put the cloth or bag over another dish and press out as much juice as possible, using this for a second quality of jelly.

Return the clear juice to the kettle, adding a pint of granulated sugar to every pint of juice. Stir until the sugar is dissolved; then place over the fire; bring to a boil; set aside and skim. Repeat this process three times; test the jelly by dropping a teaspoon on a cool saucer; and if it jellies remove the liquid and pour it into sterilized glasses.

Raspberry And Currant Jelly

Follow the recipe for Currant Jelly, using half raspberries and half currants.

Raspberry Jelly

Follow the recipe for Currant Jelly.

Blackberry Jelly

Follow the recipe for Currant Jelly.

Strawberry Jelly

To five quarts of strawberries add one quart of currants and proceed as with Currant Jelly; but boil fifteen minutes.

Green-Grape Jelly

Follow the recipe for Apple Jelly.

Ripe-Grape Jelly

Choose acid grapes, as the sweet, ripe grapes contain too much sugar. Follow the recipe for Currant Jelly.

Plum Jelly

Select under-ripe acid plums. Put them in a preserving kettle with one pint of water for every four quarts of fruit. Cook gently until the plums fall to pieces; strain the juice and proceed as with currant jelly.