How to Prepare and Store Baby Formula

Some parents feed their babies exclusively with formula, while others use it to supplement breastfeeding. Either way, it’s important to know how to prepare and store baby formula safely. Here’s how to do both.

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How to Prepare Baby Formula

Baby formula comes in three basic varieties. They are:

  • Ready-to-use (non-concentrated) liquid formula.
  • Concentrated liquid formula that you mix with water.
  • Powdered formula that you mix with water.

No matter what kind of formula you use to feed your baby, it’s important to prepare it according to the directions. Here are some dos and don’ts for safely preparing infant formula.


  • Sterilize nipples and bottles in boiling water for five minutes before you use them for the first time. After that, a thorough wash with hot water and soap is fine. (If your baby was premature or has a weakened immune system, continue to sterilize bottles until your pediatrician tells you not to.)
  • Wash your hands thoroughly before preparing bottles.
  • Use clean tap water to mix with concentrated liquid and powder formulas. (If you have well water or are unsure about the safety of your water, boil it for one minute to kill germs. Let water cool to room temperature before mixing with formula.)
  • Follow the directions on the package exactly, to ensure that your baby receives the correct amount of formula.
  • Accurately measure and add the correct amount of water to the bottle first, then add the liquid or powder concentrate. Shake the formula in the bottle instead of stirring to make sure it’s completely mixed.
  • Heat the bottle by running it under warm water or placing it in a bowl of warm water for a few minutes. (You don’t have to warm your baby’s bottles, but some babies prefer drinking warm formula.)
  • If you heat the bottle, test the temperature of the formula by shaking a few drops on the inside of your wrist. It should feel neither warm nor cold.


  • Add water to ready-to-use formula. You can pour the formula directly into the bottle.
  • Add more water than directed for concentrated formula to save money or for any other reason. According to the American Academy of Pediatrics, adding extra water will reduce the amount of nutrients your baby gets from formula. It can lead to electrolyte and mineral imbalances and slow growth and development.
  • Microwave formula. Microwaving can create hot spots in the liquid that can burn your baby’s mouth.
  • Use formula that’s past the sell-by date.

How to Store Baby Formula

For your baby’s safety, it’s important to keep track of any formula storage containers and how old they are. Pre-made formula is safe to use for up to 24 hours.

Some parents prepare one bottle at a time, while others opt to make an entire day’s worth of bottles each morning.

Here are some tips on how to store baby formula.

  • Store unopened cans of formula indoors in a cool, dry place.
  • Once you’ve opened a can of powdered formula, put it in a cool, dry place with the lid tightly sealed. Don’t put it in the refrigerator.
  • Label each prepared bottle with the date and time you prepared it. That way you won’t give your baby a bottle that’s too old.
  • Write the date on the lid of the powdered formula container when you open it. You should use it within one month after opening.
  • Give your baby a new bottle with each feeding.
  • Use prepared baby formula within two hours of preparation if it’s at room temperature.
  • Don’t keep any formula that’s left over in the bottle when your baby finishes drinking. Your baby’s saliva can mix with the formula and cause bacteria to grow.
  • If your baby decides not to eat and hasn’t touched the bottle, put it in the fridge. If it’s been at room temperature for less than two hours, it’s ok to use within the next 24 hours.
  • Throw away any unused formula that’s been at room temperature for more than two hours or refrigerated for more than 24 hours.

Feeding your baby formula can be an alternative or supplement to breastfeeding, until your baby is ready for weaning. Be sure to ask your pediatrician if you have any questions about preparing or storing formula.

CDC, Infant Formula Preparation and Storage, Link

CDC, How to Prepare and Store Powdered Infant Formula, Link, Formula Feeding FAQs: Preparation and Storage, Link

American Academy of Pediatrics, How to Safely Prepare Baby Formula With Water, Link

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Built upon our flagship, UPMC Magee-Womens Hospital in Pittsburgh, and its century-plus history of providing high-quality medical care for people at all stages of life, UPMC Magee-Womens is nationally renowned for its outstanding care for women and their families.

Our Magee-Womens network – from women’s imaging centers and specialty care to outpatient and hospital-based services – provides care throughout Pennsylvania, so the help you need is always close to home. More than 25,000 babies are born at our network hospitals each year, with 10,000 of those babies born at UPMC Magee in Pittsburgh, home to one of the largest NICUs in the country. The Department of Health and Human Services recognizes Magee in Pittsburgh as a National Center of Excellence in Women’s Health; U.S. News & World Report ranks Magee nationally in gynecology. The Magee-Womens Research Institute was the first and is the largest research institute in the U.S. devoted exclusively to women’s health and reproductive biology, with locations in Pittsburgh and Erie.


About Pediatrics

From nutrition to illnesses, from athletics to school, children will face many challenges growing up. Parents often will make important health care decisions for them. We hope to help guide both of you in that journey. UPMC Children’s Hospital of Pittsburgh is a national leader in pediatric care, ranking consistently on U.S. News & World Report’s Best Children’s Hospitals Honor Roll. We provide expert treatment for pediatric diseases, along well-child visits, urgent care, and more. With locations across Pennsylvania, Maryland, and West Virginia, you can find world-class care close to home. We also work closely with UPMC Magee-Womens Hospital, a national leader in care for newborns and their mothers. Our goal is to provide the best care for your children, from birth to adulthood and beyond. Visit our website to find a doctor near you.