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How to Choose, Prepare and Store Infant Formula


How to Choose, Prepare and Store Infant Formula


Breastmilk is the only food your baby needs for the first 6 months. Breastfeeding can continue even after starting solid foods until 12 months and beyond.

If you are considering using infant formula, talk to your health care provider for support with your infant feeding choices.

Any amount of breastfeeding has important health benefits for both you and your baby. If you are considering formula feeding because you think you may not be making enough milk, learn more about the signs your baby is getting enough milk and talk to your healthcare provider.

There are risks associated with using formula and for some women it can be difficult to return to breastfeeding when formula is introduced. Your health care provider can help you decide if formula feeding is right for you and your baby and how to supplement your baby if you need or want to do so. Your health care provider can also give you specific advice if your baby was born early (pre-term) or has a medical condition.

There are 3 types of infant formula and each has its own specifics:

  • Powdered: not sterile and may have bacteria that can make your baby sick. It’s made using boiled water.
  • Concentrated liquid: sterile and is made using boiled water.
  • Ready-to-feed: sterile and the safest for all babies.

Don’t mix different types of infant formula together – follow the directions exactly. The headers below link to printable PDF's that have instuctions on how to make each kind, including how to properly clean all the equipment you’ll need.

How to Clean and Disinfect | How to Prepare Ready-to-Feed Formula
How to Prepare Concentrated Liquid Formula | How to Prepare Powdered Formula


Formula Feeding

Choosing and Buying Infant Formula

  • Always feed your baby store-bought infant formula. These are made by formula companies to meet safety standards set by Health Canada.
  • Buy infant formula at most grocery stores and pharmacies. Be careful when buying infant formula on the internet. If shipped from other countries, these products may not be the same as what is sold in Canada.
  • Don’t give your baby homemade formulas using recipes found on the internet. Formula made using home ingredients may not be safe and may not give your baby all of the nutrition they need.
  • Check the “use by” or “expiry date” on the package. Do not buy infant formula if it is past the expiry date.
  • Make sure the bottles, cans and tetra-packs aren’t dented or damaged before you buy them.
  • Store unopened bottles, cans or tetra-packs in a cool, dry place.

Choosing a Water Source

Most tap water can be boiled to make infant formula. Use “cold” water for boiling because “hot” water from the tap may have higher amounts of lead or other minerals. Let “cold” water run from the tap for at least 1 minute. This will help get rid of any minerals that have built up overnight. Or use bottled water purchased at a store. Do not use carbonated or mineral waters.

Do you have softened water in your home? Water softeners may raise the level of sodium in drinking water. This may be safe for adults but should not be used to make infant formula.

If you use water from a well, or are unsure if your tap water is safe, contact your local public health unit.

If you do not have a safe source of drinking water, use ready-to-feed formula.

Boiling Water to Prepare Infant Formula

  • Boil all water used to make infant formula from powder and concentrated liquid. The water must reach a rolling boil for at least 2 minutes. Warm water will not kill bacteria.
  • Cool the water at room temperature until it reaches 70°C. This takes about 30 minutes. You can use a digital thermometer to check the water.
  • For concentrated liquid formula you may use water that has been boiled and cooled to room temperature as long as your baby is healthy and you:
    • feed it to your baby immediately after mixing
    • throw out any formula that has not been used within 2 hours.

Storing Formula After it is Mixed with Water

  • Prepare only one bottle of formula at a time. This allows the formula to cool faster. Make sure that it is kept in the fridge at a temperature of 4°C for no longer than 24 hours.
  • Don’t put formula on the fridge door. Temperatures may be warmer on the door than other areas of the refrigerator.
  • Throw out any formula left in the bottle if your baby does not drink it within 2 hours. Don’t freeze formula. Freezing may cause it to be grainy or cause fat to separate from the rest of the formula.

Warming Formula for Feeding

  • Never warm formula in the microwave. Microwaves can’t heat the formula evenly and there may be hotspots that can scald your baby’s mouth.
  • Formula can be fed to your baby cold, at room temperature or warm, right away.
  • Warm formula up by holding the bottle under hot water or placing the bottle in a bowl with hot water. Make sure that the water does not touch the nipple or lid of the bottle.
  • Warming shouldn’t last longer than 15 minutes. Gently shake or swirl the formula in the bottle.
  • Test the temperature of the formula by sprinkling a couple of drops onto your wrist. The formula should feel warm but not hot.
  • Never warm a bottle of formula more than once.

You can start to introduce solid foods to your baby at about 6 months of age. Starting at 9 months you can offer pasteurized whole cow milk (3.25% Milk Fat). Talk to your health care provider, call 8-1-1 to speak with a registered dietitian or nurse, or email a HealthLinkBC dietitian for more information about feeding your baby formula.

Resources & Links:

HealthLinkBC: Feeding Your Baby With Infant Formula: Before You Start
HealthLinkBC: Feeding Your Infant
All About Supplementing

Last Updated: January 29, 2018