Formula Feeding FAQs: Preparation and Storage_KH_Parent

Formula Feeding FAQs: Preparation and Storage

The major health organizations — including the American Academy of Pediatrics (AAP), American Medical Association (AMA), the American Dietetic Association (ADA), and the World Health Organization (WHO) — agree that breast milk is the ideal form of nutrition for babies (especially during the first 6 months). However, only you can decide what's best for you and your baby. And commercially prepared formulas are designed and strictly regulated to provide the nutrients your baby needs.

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 questions about formula feeding.

Do I need to sterilize my baby's bottles?

Yes. 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, you'll 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?

How you actually prepare the bottles depends on the type of formula you buy. Follow the instructions on the label exactly, using the precise amounts of water and formula specified. Both using too much water or too much formula can cause problems for your baby.

For babies up to 6 months of age, it's recommended that you boil the water that you add to concentrated or powdered formula. Though municipal water is typically fine, there is the possibility that the water supply can become contaminated. The U.S. Food and Drug Administration (FDA) says you should bring water to a very bubbly boil, keep it boiling for 1 to 2 minutes, then let it cool. (When using tap water, run it on cold for 2 minutes to help flush out any lead or other impurities.)

There's also bottled water available for infant use. Some of these products have added fluoride, so check with your doctor before using them. And unless the bottle's label indicates that it's sterile, you'll need to boil it as well.

How do I warm my baby's bottles?

Some babies may actually prefer cold or room-temperature bottles to warm, especially if you start serving them that way from the get-go (which can make things easier for you in the long run). But if your baby does prefer a warm bottle, remember that the microwave can create dangerous "hot spots" in bottles, so you should never microwave formula.

Instead, you can:

  • Run the bottle under very warm or hot water for a few minutes.
  • Put your baby's bottles in a pan of hot water. Just be sure to remove the pan from the heat source before placing the bottle in it.
  • Use bottle warmers that either sit on your countertop at home or plug into your car's lighter.

Whichever way you choose to heat your baby's bottles, be sure to shake the bottle vigorously. Then test the temperature of the formula by squirting a drop or two on the inside or your wrist before feeding your baby. It should be lukewarm (barely warm) not hot.

How long can mixed formula keep in the fridge?

You should always refrigerate any bottles you fill for later feedings to prevent bacteria from growing, as well as any open containers of ready-to-feed or concentrate formula. Throw away any mixed formula after 24 hours and any open ready-to-feed or concentrate formula after 48 hours.

How long can a bottle keep at room temperature?

Discard any prepared or ready-to-feed formula that's been sitting out after 1 hour.

If formula is left over, can I offer it again?

No, throw away any leftover formula. There's a chance bacteria may have formed since the last feeding, which could make your baby sick.  

Reviewed by: Larissa Hirsch, MD
Date reviewed: March 2009

Related Sites

U.S. Food and Drug Administration (FDA)
American Dietetic Association
Women, Infants, and Children (WIC)
American Academy of Pediatrics (AAP)
American Academy of Family Physicians

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Formula Feeding FAQs: Getting Started
Formula Feeding FAQs: Some Common Concerns