Using a sharp knife, cut the corn kernels from the cobs and reserve in a large bowl.

Using a spoon, scrape the milky liquid from the cob into the bowl of kernels.

Thinly slice the cabbage and chop medium fine.

Cut the green and red peppers into thin strips and dice.

Chop the onions.

In the kettle, bring 1 quart of the vinegar to a simmer over moderate heat.

Whisk in the flour, sugar, salt, dry mustard, and turmeric.

Add the remaining 1 quart vinegar and simmer for 30 minutes.

Ladle the relish into sterilized jars and seal.