Clean, wash fruit and take off all stems and pick out bad ones. Put in large kettle. Squash a bit to make a little juice and add 1/2 cup water. Put on high and then simmer covered, stirring once in a while so fruit does not stick to pot until juices are out of fruit (skins are loose and some of the pits too). Drain or drip on cheese cloth for 2-3 hours.
Measure juice into very large pot (no more than 6 cups of juice at a time). For each cup of juice, you will be using 1 cup of sugar. Put sugar in separate bowl or pot with handle. Heat juice until it comes to hard rolling boil. Add sugar very gradually and stir until dissolved, keeping mixture boiling (do not allow boiling to stop).
After last sugar is placed in and dissolved completely, let boil; do not touch (jellying time) for 3 minutes. Then begin testing by dipping soup spoon and watching the drips of the spoon slowly dripping back to pot. If it drips like water, jelly is not ready. If it drips very slowly, one drop at a time, and drops joining together as it drops to back to pot, then it is ready. Do not boil any more than 6 minutes.
Look up "jelly testing" in cookbooks with pictures to tell you when it is ready. Place jelly in sterilized jars. Let cool; do not move until fully cooled. Seal with wax. 7 cups juice plus 7 cups sugar equals 8 jars jelly.