Wash your hands before you start. Follow the directions on the label carefully about how to mix formula, whether to shake it, how to store it, and how long you can keep opened containers before discarding. With liquid formula, double-check whether it needs to be diluted. It is important not to make formula stronger or
weaker than it is supposed to be. If you change brands or types, check the label; the directions may be different.
Prepare no more than a day’s worth at a time. You can either fill the bottles, cap them, and refrigerate them or prepare the formula in a clean (or sterilized) jar, refrigerate it, and fill the bottles as you need them. Do not freeze formula. Once your baby has drunk from a bottle, discard whatever is left. If your baby dozes off while eating and wakes in a few minutes, it’s OK to keep using the same bottle, but don’t save leftovers for a later feeding. The formula may have become contaminated with bacteria.
If you’re taking filled bottles on an outing, pack them in an insulated bag with an ice pack, ice cubes, or a frozen juice box. To be safe, the formula should still feel cold to the touch at the time you use it. A safe alternative is to take along unopened single-serving cans and clean, capped bottles. Then fill a bottle just before feeding. Most babies seem to do fine with formula whether it is cold (straight from the refrigerator) or slightly warmed (to room temperature or to body temperature).
Babies may have individual preferences or may become used to a certain temperature.
Follow these directions to warm refrigerated formula:
• Hold the bottle for a few moments under warm running water, or put it in a bowl of warm water.
• At night, you may want to use an electric bottle warmer. These devices are usually kept at the bedside. They keep a bottle cold until you need it, then rapidly warm it, saving you a trip to the refrigerator.
• Do not use a microwave to warm a bottle. The bottle may feel cool to the touch but still have hot spots inside that can burn your baby.
• Do not let a bottle sit at room temperature to get warm for more than a few minutes.
• Test the temperature of the formula by dripping a few drops onto the inside of your wrist. It should feel neutral, neither cold nor warm.
Offer a Little Extra
How much should you put in your baby’s bottle? An ounce or two more than she usually eats. That way, if she’s extra hungry or her appetite is growing, she’ll still get enough. If you give her only what she eats, so that she always empties the bottle, you’ll never know if she would have taken more if it had been available.