Blast chilling is a method of cooling food quickly to a low temperature that is relatively safe from bacterial growth. Bacteria multiply fastest between +8 °C (46 °F) and +68 °C (154 °F). By reducing the temperature of cooked food from +70 °C (158 °F) to +3 °C (37 °F) or below within 90 minutes, the food is rendered safe for storage and later consumption. This method of preserving food is commonly used in food catering and, recently, in the preparation of 'instant' foods, as it ensures the safety and the quality of the food product.