This article presents a calculation procedure useful for the optimization and scale up of batch sterilization cycles in large-scale fermentors. This technique determines the sterilization temperature and hold-time necessary to minimize nutrient damage in a specific fermentor. The method can also be used for “scaledown” experiments to eliminate sterilization conditions as a scale up parameter. A method for the systematic evaluation of different sterilization conditions on product yield is also presented. This procedure is useful in determining if scale up of sterilization conditions is important for a given process. The validity of the techniques presented are supported by data showing significant yield improvements in a 1.2 × 105 L antibiotic fermentation.