After the fruit is strained, measure it, and place it in the preserving kettle; measure an equal amount of granulated sugar, and set it aside. When the juice has reached the boiling point, let it cook gently for twenty minutes, then stir in half of the sugar and boil for ten minutes; now stir in the rest of the sugar, taking care that it is well distributed. As soon as the sugar has dissolved, test a little of the jelly on a cold plate. It should be stiff and clear. If this is not the case, you may cook the jelly five to ten minutes longer, testing from time to time. If all directions are carefully observed, jelly made according to this formula is clear, firm, and has a fine flavor.