Remove husks and silk from corn just before cooking. Bring 7 quarts water to a boil in a stainless steel stockpot; add corn. Return to a boil; boil 5 minutes. Drain.
Cut corn from cob to measure about 2 quarts. Combine corn kernels and remaining ingredients in stockpot. Bring to a boil. Reduce heat; simmer, uncovered, 20 minutes, stirring frequently.
Quickly ladle relish into hot sterilized jars, leaving 1/2-inch head space. Remove air bubbles. Cover with metal lids, and screw bands tight. Process in boiling water bath 15 minutes.