If you really want to make the soup when corn is out of season, go ahead and use a 1-pound bag of frozen (defrosted) corn. This is delicious made either way, so you can have it throughout the year.

1 medium potato, peeled and diced small (about 2 cups diced)
2 1/2 cups water
1 tablespoon butter
1 1/2 cups minced onion
1/2 teaspoon dried thyme
1 1/2 teaspoons salt (or to taste)
1 medium stalk celery, finely minced
1 small red bell pepper, finely minced
5 cups (approximately 4 to 5 cobs' worth) fresh sweet corn
White pepper to taste
3 tablespoons minced fresh basil (or more, to taste)
1 cup milk, at room temperature (lowfat OK)

1. Place the potatoes and water in a small saucepan. Bring to a boil, lower to a simmer, cover, and cook until the potatoes are tender. Set aside.
2. Melt the butter in a kettle or Dutch oven. Add the onion, thyme, and salt, and cook over medium-low heat, stirring. After about 5 minutes, add celery. Five minutes later add the cooked potatoes with all their liquid, the red bell pepper, the corn, and a few shakes of white pepper. Stir well, cover, and reduce heat. Cook quietly for about 5 minutes longer.
3. Using a blender or food processor, purée about half the solids (about 2 to 3 cups--it doesn't have to be exact!) in some of the soup's own liquid. Return this to the kettle, and let it rest until serving time.
4. Stir in the basil and milk about 10 minutes before serving time. Don't actually cook the soup any further; simply heat it--gently!-- until it's hot enough to eat. Serve immediately.