Place one quart canning jar and a ring into a pot of water. Bring to a rolling boil for five minutes. Meanwhile, put a canning lid into a small pot and bring to a simmer.
Cut corn off the cobs. (A good way to do this is to place a paper bowl upside down in a large mixing bowl, and rest the stem end of the cob on the bowl. This allows you to slice the corn straight into the bowl without nicking your knife.).
Carefully remove the jar from the water and drain. Add salt, vinegar and sugar. Pack the corn into the jar (4 1/2 lbs of corn-on-the-cob should make about 1 quart). Fill jar with water, leaving 1" headspace. Set the lid on the jar and loosely set the ring in place.
Store jar in a cool place for 1-2 weeks, then tighten the ring and store in the refrigerator until ready to use.
Suggestion: rinse well with cold water, drain thoroughly, then saute in bacon grease with diced onion, and red and/or green bell pepper. Add crumbled bacon before serving.