A food establishment shall obtain a variance from the department before smoking or curing food; using a reduced oxygen method of packaging food except as specified under section 271-2.24 of this Subpart where a barrier to Clostridium botulinum in addition to refrigeration exists; custom processing animals that are for personal use as food and not for sale or service in a food establishment; or preparing food by another method that is determined by the department to require a variance.