Cut kernels from cobs (should have about 6 cups). In a 4-quart Dutch oven bring 2 quarts lightly salted water to boiling. Add the corn; return to boiling. Cook, uncovered, for 1½ minutes, stirring occasionally. Drain well; set aside.
In a large saucepan, heat the oil over medium heat. Add the apple, carrot, onion and garlic; cook and stir for 3 to 4 minutes or until vegetables are tender but not brown. Add the chicken broth. Bring to boiling; reduce heat. Cover and cook 2 minutes more.
Cool the vegetable mixture slightly, about 10 minutes. Add half the cooked corn (about 2½ cups). Place the vegetable mixture, one-third at a time, in a blender jar or food processor bowl. Cover and blend or process until nearly smooth; return to large saucepan; add the remaining corn; heat through. Season to taste with salt and pepper.
To serve, ladle the soup into bowls. Top with a pat of butter and a sprinkle of thyme. Serve with lime wedges for squeezing and Tabasco sauce, optional.