Whether you've decided to formula feed your baby from the start, are supplementing your breast milk with formula, or are switching from breast milk to formula, you're bound to have questions. Here are answers to some common queries about formula feeding.

Do I need to sterilize my baby's bottles?
Before the first use, you'll need to sterilize nipples and bottles in a rolling boil for 5 minutes. You can also sterilize them with a store-bought countertop or microwaveable sterilizer, but boiling works just as well and costs nothing.
After that, it's not necessary to sterilize your baby's bottles and supplies each time you feed your baby. You will need to wash bottles and nipples in hot, soapy water (or run them through the dishwasher) after every use. They can transmit bacteria if not cleaned properly.
How do I prepare my baby's bottles?
Prepare your baby's formula by mixing water and the appropriate amount of powdered infant formula. The packaging on the side of the formula container will tell you how much to use. Carefully follow the directions. You can use tepid (room temperature) tap water, as long as your local or state health departments have labeled it as safe to drink.
If you're concerned about your water, you may sterilize it to kill germs. Here's how:
- pour cold tap water into a teapot or saucepan
- place pot on the stove over medium heat
- bring water to a rolling boil, and let boil for about a minute
- let the water cool until it's at room temperature
Test to see if the water is cool enough for your baby to drink by shaking a few drops of water on the inside of your wrist. If it stings, it's still too hot. Once water has cooled, don't let it sit longer than 30 minutes before adding it to the formula.
Once prepared, the formula is ready to feed to your baby immediately without additional refrigeration or warming. Formula that's been prepared should be consumed or stored in the refrigerator within 1 hour. If it has been at room temperature for more than 1 hour, throw it away. And if your baby doesn't drink all the formula in the bottle, throw away the unused portion — do not save it for later.
Formula may be prepared ahead of time (for up to 24 hours) if you store it in the refrigerator to prevent the formation of bacteria. Open containers of ready-made formula, concentrated formula, and formula prepared from concentrate also can be stored safely in the refrigerator for up to 48 hours.