The time required to reduce the population of viable microbial spores ten-fold in the thermal sterilization process of foods that may be contaminated with harmful spores. Twelve successive reductions is known as a botulinum cook or a 12-D process. This is deemed to be sufficient to reduce statistically any potential spores of the highly pathogenic microorganism Clostridium botulinum to insignificant levels. This bacterium produces a highly toxic toxin which is destroyed in the cooking process.