A process for producing precooked bacon slices comprising the steps of (a) conveying bacon slices through a spiral oven, (b) indirectly cooking the bacon slices in the spiral oven using a cooking medium which is circulated within the oven at a low rate sufficient to prevent the bacon slices from being displaced on the conveyor, and (c) adding steam to the cooking medium as necessary to at least reduce the percentage or substantially eliminate the presence of air in the cooking medium.