From 1913:
For this purpose the wild or “fox” grapes, as they are called in some parts of the country, are the best. Strip them from the stems and wash them, then put them into the preserving kettle with the water which adheres to them and heat them slowly. It is well to lay an inverted plate in the bottom of the kettle that the grapes may not stick and scorch. Especially is this necessary if the cooking is done over gas. In this case it is better to set the kettle on an asbestos mat placed over the flame. When the grapes are broken to pieces by the cooking crush them still more with a paddle or wooden spoon, turn them into a jelly bag let the juice drip through and measure this. To each pint of it allow a pound and a half of sugar. Return the juice to the fire, bring it to a boil and after it has cooked for teen minutes put in the sugar, which it is well to heat in pans in the oven; it should be hot through, but not melted. As soon as the sugar is dissolved in the juice and this returns to the boil, take from the fire and put into glasses, rinsing these out in boiling water. Put a spoon in each before pouring in the hot jelly, to save the chance of cracking.