A method and apparatus for treating processed food casing in preparation for stuffing. The method includes extending the casing, applying (e.g., spraying) an organic acid (e.g., a citric acid solution) to the exterior surface of the casing to produce a treated casing, and mounting the treated casing onto a stuffer. In one embodiment, extending includes removing the casing from a brine solution and laying the casing onto a support surface (e.g., attaching to a movable conveyor). The casing in the brine solution is commonly attached to a ring, and preferably attaching includes hooking the ring onto an engagement member on the conveyor. If desired, the method can also include rinsing the casing (e.g., spraying a water solution onto an exterior surface of the casing) after extending the casing and before and/or after applying the organic acid.