A commercial kitchen should undergo a deep clean at least once every six months to a year, depending on the level of usage, the type of food being prepared, and local health and safety regulations. This thorough cleaning includes not only the equipment but also hard-to-reach areas, walls, floors, and storage spaces. Regular deep cleaning helps maintain hygiene, prevent cross-contamination, and ensure compliance with health standards. For kitchens with high-volume operations, deep cleaning might be required more frequently, possibly every 3-4 months.