If you don't have a chef's torch you can broil the tops of creme brûlée. Place the ramekins on a baking sheet (only a couple at a time), and arrange the rack in the oven to the highest position. Turn on the broiler and broil for 5 to 8 minutes. Watch carefully and if possible rotate the ramekins with tongs to evenly broil the tops. The tops will harden once the brûlée cools.