Believe it or not, there is much confusion surrounding this topic. Many parents believe that cooled boiled water means water that has been brought to the boiling point and then refrigerated. In actual fact, cooled boiled water refers to boiled water that has been cooled for no more than 30 minutes (so it’s no cooler than 70 degrees) after boiling. It is the recommended method for making formula and needs to be consumed immediately after mixing to avoid bacteria growth.
According to the World Health Organisation (WHO):
For infants at greatest risk, sterile liquid infant formula should be used where available. If powdered infant formula is used, correct preparation and storage reduces the risk of illness. Powdered infant formula should be prepared with water that is no cooler than 70ºC (in order to kill E. sakazakii) and prepared feeds should be consumed immediately or stored in a refrigerator (to prevent growth of E. sakazakii).
Unlike commercial liquid formulas that are safe to consume, powdered infant formula cannot achieve commercial sterility. Bacteria has been found in infant formula and if not prepared fresh, can cause a life-threatening infection such as Cronobacter sakazakii and salmonella. Therefore, it is necessary to follow the guidelines endorsed by WHO, FAO and other medical organizations.1 | 2 | 3