Formula prep without stress

Use fresh water boiled and cooled to about 70°C (158°F) to kill harmful bacteria that can live in powdered formula. Ready-to-feed and liquid concentrate formulas are already sterile and don't need this step. Measure water into the bottle first, then add the correct number of scoops of powder. Reversing the order can throw off the concentration. Mix by rolling the bottle between your hands or gently swirling — not vigorous shaking, which creates foam and bubbles. Prepared bottles keep 2 hours at room temperature or 24 hours in the fridge if refrigerated immediately. Any formula your baby started drinking should be finished within an hour or discarded — bacteria multiply quickly once saliva enters the bottle.