4 ears fresh corn, husked
2 tablespoons butter, softened
1/4 teaspoon freshly grated lime zest
1 teaspoon lime juice
1/2 teaspoon minced chipotle pepper in adobo sauce plus 1/4 teaspoon adobo sauce (see Ingredient Note) or 1/4 teaspoon ground chipotle pepper
1/2 teaspoon kosher salt