By employing this test, sugar can often be reduced, and thus the jelly texture will be fine, less rubbery and the flavor will be better.
After the fruit has been selected and prepared as usual by washing, stemming, and so forth, it is ready to be heated in an acid-proof kettle. With juicy fruits use just enough water to prevent burning—about one cup of water to every four or five quarts of fruit. The juicy fruits are currants, raspberries, and so forth. With less juicy fruits, as apples or quinces, use enough water to cover, or follow the rule, half as much water as fruit. Use the cores, skins and seeds; these improve the flavor and color of the jelly.
Berries can be mashed. Heat the fruit slowly in a covered kettle, stirring once in a while to obtain an even cooking. When the simmering point is reached, crush the fruit with a well-soaked wooden masher. When the fruit is tender or has a transparent appearance, it is ready to strain.
The jelly bag must be of closely woven material; one with a large mouth is advisable. If cheesecloth is used double it and tie opposite corners together. When a very clear jelly is desired use a flannel or felt bag for straining the juice.
What drips into the dish or pan is called Extraction One. When this Extraction One is fairly drained out, which takes about thirty minutes, do not squeeze the pulp for a second grade jelly as so many housewives do; instead, make another juice extraction. To do this, empty the contents or pulp in the bag into the preserving kettle, cover with water, and stir until thoroughly mixed; then cover, bring slowly to a boil as before and drain again. The juice that drips out is called Extraction Two.
The pectin-alcohol test can be used here again to find out whether there is much or little or no pectin left. If much pectin is present, you can repeat the operation and get Extraction Three.
Three extractions usually exhaust the pectin, but sometimes you can get as many as five extractions.
You may say, "Why bother with extractions—why not squeeze the juice and be done with it?" You will get clearer, better-flavored and more glasses of jelly if you will make the extractions than if you squeeze the jelly bag.
I always make the jelly from Extraction One by itself, but usually combine Extraction Two and Three.
The next step in jelly making is vitally important—that is, how much sugar to use to a given amount of fruit juice. This is where many housewives "fall down" on jelly making. They use the same proportion of sugar to all juices.