How to Prepare Premade Formula for Your Baby

How to Use and Store Ready-to-Feed Formula Safely

Many parents choose ready-to-feed formula for their infants. Premade formula is considered the easiest formula to make because it does not require much preparation or mixing. It can be served at room temperature or warmed up slightly.

Before you prepare your baby's bottle, make sure you have the right premade formula for your child. Infants require infant formula, not toddler versions. Also check the type of formula, which comes in ready-to-feed, concentrated, and powdered varieties. Once you have determined that you have the right formula and the right supplies, it is time to prepare the baby bottle.


Read the Instructions for Ready-to-Feed Formula

Dad bottle feeding baby

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Many types of infant formula look alike. Be sure to read the directions prior to mixing your baby's bottle. A ready-to-feed formula should be labeled: Do Not Add Water.

Adding water to this formula can lead to malnutrition in your baby. Ready-to-feed formula already has the right amount of water in it.

Adding more would dilute it, making it less nutrient dense. Most ready-to-feed formulas are very simple and follow the basic instructions below. Read the manufacturer's direction on the container before starting.


Gather Your Supplies

For ready-to-feed infant formula you will need to gather the following supplies:

  • A clean baby bottle with measurements on the side
  • Bottle collar and clean nipple
  • Bottle opener with triangular tip (if using canned formula)
  • Ready-to-feed formula, either in a can or a plastic bottle

You may also wish to have a baby bib or burp cloth. This is for both during the feeding and after the feeding when you burp the baby. Some babies also spit up or drool formula out of their mouths while feeding. A bib will help keep you and your baby clean.


Make a Bottle

Before making the bottle, wash your hands like you would for preparing any food. If you are using canned formula, take your can opener and punch a hole in one side of the top of the formula can. Punch an additional hole directly across from the first hole. This will allow it to flow better when pouring.

If using bottled formula, unscrew the lid and open the seal, if any. If using a previously opened bottle, make sure it hasn't been opened for longer than 48 hours and that it has been stored properly. Determine how much formula your baby needs at this feeding and pour exactly that amount in the baby bottle.

Do not pour more than you need because it is not able to be saved for later.


Warm Baby Bottles With Caution

If you are feeding baby formula that was stored in the refrigerator, you will likely need to warm it up. Most babies will not drink cold formula, though it is safe to do so. Never put a baby bottle in the microwave to heat up. Instead, place the bottle in a bowl of warm water. A 2-cup plastic food storage container is a good size for baby bottles.

If you do not have ready access to warm water, you can microwave a bowl of water for 30 seconds, then place the baby bottle inside to warm to room temperature. It should not take more than 5 minutes and do not leave the bottle in the water for more than 15 minutes, as the heat may degrade the formula.

Some parents prefer to use bottle warmers because they are fast and easy to use, especially for middle-of-the-night feedings.

Warmers typically require a little water that goes over a heating device to created steam. The baby bottle sits in a basket above the heat source to keep it from getting too hot.

Once the bottle is warm, shake it well, and check the temperature. An easy way to do this is to squirt a little on the inside of your wrist. If it feels too warm, let it cool a bit before testing again. When the formula reaches the right temperature—not too hot and not too cold—you can feed the bottle to your baby.


Store Leftovers Properly

If there is formula leftover in the can or original container after pouring your baby's bottle, it should be stored in the refrigerator. It will last for 48 hours in the fridge. If using a can, cover the top with plastic wrap and a rubber band or with a special lid designed to cover the can top to preserve freshness.

Some containers of ready-to-feed formula are considered single feedings, typically 8 ounces. If your baby is drinking less than this, store the leftovers properly. Do not save leftover formula from the bottle your baby drank from. Once a bottle is started, it is good for 1 hour at room temperature, then must be discarded.

By Robin Elise Weiss, PhD, MPH
Robin Elise Weiss, PhD, MPH is a professor, author, childbirth and postpartum educator, certified doula, and lactation counselor.