This section is from the book "Mrs. Rorer's Vegetable Cookery And Meat Substitutes", by Sarah Tyson Rorer. Also available from Amazon: Mrs. Rorer's Vegetable Cookery And Meat Substitutes.......
This, with the exception of peas, is the most difficult of all vegetables to keep. Corn must be perfectly fresh from the field. Remove the husks, cut the tips from the grains, or score them down the centre, and press out the pulp. Pack this pulp at once into perfectly clean glass jars, filling the jars within one inch of the top; adjust the rubbers and lay on the tops. Stand the jars in a boiler as directed in preceding recipes, and surround them with cold water. Cover the boiler, and after the water begins to boil, boil for three hours. Lift one jar at a time and fasten the top; do not lift the lid. Then add sufficient boiling water to entirely cover the jars and boil for one hour. Let them cool in the boiler, taking it, of course, away from the fire.
I have used this recipe for years, and have never had a single jar to spoil.