Remove husks and silks from corn; cut corn from cobs (do not scrape cobs). Measure 8 cups of corn. In an 8 to 10-quart stainless-steel, enamel, or nonstick heavy kettle or pot combine corn and the 2 cups water. Bring to boiling; reduce heat. Simmer, covered, for 4 to 5 minutes or until corn is nearly tender; drain.
In the same kettle, combine cooked corn, celery, red and green sweet pepper, and onion. Stir in vinegar, sugar, mustard, pickling salt, celery seeds, and turmeric. Bring to boiling. Boil gently, uncovered, for 5 minutes, stirring occasionally. Stir together fruit pectin and the 2 tablespoons water; add to corn mixture. Cook and stir until slightly thickened and bubbly; cook and stir for 2 minutes more.
Ladle hot relish into hot, clean half-pint or pint canning jars, leaving a 1/2-inch headspace. Wipe jar rims; adjust lids. Process filled jars in a boiling water canner for 15 minutes (start timing when water returns to boil). Remove the jars from canner; cool on wire racks.
CUMIN-POBLANO CORN RELISH: Use 1 1/2 cups chopped poblano peppers in place of the 1 1/2 cups chopped green sweet pepper. Reduce vinegar to 2 cups and add 1/2 cup lime juice. Omit celery seeds and turmeric and replace with 1 tablespoon ground cumin.
APPLE CORN CHUTNEY: Reduce corn to 6 cups and add 2 cups chopped granny smith apples with the celery, sweet peppers and onion. Omit celery seeds and turmeric; replace with 2 teaspoons caraway seeds.
CORN OLIVE RELISH: Add 1 cup coarsely chopped pitted green olives and 1 cup coarsely chopped pitted black olives with the celery, sweet peppers, and onion.