Which of the following is not considered a food contact surface?

The correct answer is the freezer walls. Food contact surfaces are defined as surfaces that directly touch food during the preparation, cooking, or serving processes. Cutting boards, food storage containers, and cooking utensils all serve that essential function by coming into direct contact with food items, either holding, chopping, or serving them.

In contrast, the walls of a freezer do not come into direct contact with food but serve as the structure that holds the food storage space. While they play a supporting role in food storage by maintaining a safe temperature, they are not involved in the direct handling or preparation of food. Therefore, they do not meet the criteria of a food contact surface, making this option the correct choice.