My family loves orange marmalade, and it is relatively easy to make. I have stopped preserving mine in a canner, and instead place it in freezer containers or Ball jars and store it in the freezer. It does not seem to affect the quality at all. This recipe is very old, and came from an older edition of the Joy Cookbook. I've made it several times with good results, and no pectin is needed.
Scrub the fruit well, cut into quarters, and remove the seeds. Catch the juice in a bowl. Place all the fruit, including peels, and the juice, into a large container and add the 10 cups water. Soak for 24 hours.
The next day, remove the fruit from the water and cut into very fine shreds. Turn fruit and water into a large kettle. Boil 1 hour.
While fruit is boiling, sterilize jelly glasses as directed by manufacturer. I keep mine hot on a paper-towel-lined baking pan in a 200° oven.
Add the 8 cups sugar and continue to boil until the marmalade forms a jelly consistency when tested. Begin to test 10 minutes after the sugar has been added. To test, use jelly thermometer to 220°. Or, use the spoon test, as shown in the picture. (The Joy of Cooking, 1975, Bobs-Merrill Co.)
When marmalade reaches the jelly stage, carefully ladle into the prepared jelly glasses. Put on lids, invert for 2-3 minutes, then turn upright and allow to cool to room temperature. I store mine in the refrigerator (2-3 jars) or freezer (the rest of the jars). Or, you can water-bath process according to your canner directions for jelly.