7. Know when to throw or store

If your baby doesn't drink all the formula in the bottle in an hour, throw the rest away. Bacteria from your baby's saliva can grow in the formula, even if the bottle is in the fridge.

If you've poured ready-to-feed formula into the baby's bottle but have some left over in the original container, you can cover and refrigerate it. Throw away any leftover ready-to-feed formula that's been in the refrigerator more than 24 hours.

Sometimes it makes sense to get bottles ready before you need them. If you want to prepare a few bottles of formula for the future, do the following:

• Add a label that says the day and time the bottle was made.
• Keep bottles cold but not frozen, ideally in the refrigerator.
• If the bottles have been in the fridge for more than 24 hours, toss them.

If you're not sure whether a container or bottle of formula is safe, throw it out.