Combine 4 cups water, garlic, 1 1/2 teaspoons salt and 1 1/2 teaspoons pepper in a large stockpot or Dutch oven over medium heat. Bring to a boil; reduce heat and simmer for 10 minutes.
Stir in milk, butter and brown sugar. Bring to a boil; working carefully, add corn, reduce heat and simmer until just tender, about 10 minutes.
Serve immediately, garnished with chives, if desired.