Read time: 7 minutes

What should I know about preparing and storing infant formula?

• Learn how to prepare powdered, concentrated, and ready-to-feed infant formulas
• Understand how to properly store prepared infant formula

Good news! Whether powdered, ready-to-use, or concentrate, formula package instructions usually include all the information you need to easily prepare a bottle. For all the extra details on formula preparation and storage, read on.

Safety first before preparing baby formula

Practicing proper hygiene is key when preparing formula. Your baby’s immune system is still developing so minimizing unnecessary exposure to bacteria can help decrease the risk of infections.^{2, 3}

Check the Expiration or Use By date
Note the ‘Expiration Date’ and/or ‘Use By’ date on the formula packaging. It is not recommended to use formula after its Use By or Expiration date as the quality and content of the nutrients may not be guaranteed.^{2, 3} Make sure the cans or containers are not dented or have rust.⁴

Work in a clean area with clean bottles and equipment
Wash your hands and countertop thoroughly before handling baby bottles and formula.⁵

If you’re using the bottles for the first time, sterilizing the bottles along with their parts is a good precautionary measure.² Simply boil the items for 5 minutes and then let cool before handling.

Otherwise, clean the bottles, bottle liners, and nipples in hot soapy water and rinse well.⁵ You can use a special bottlebrush to clean any hard-to-reach spots.

Read more: Choosing the right bottles and nipples

Preparing infant formula

Most important: Unless your doctor tells you otherwise, you should use only the amount of water as directed on the formula packaging.

Following the preparation instructions exactly is important to ensure your baby receives proper nutrients. Too much water will dilute the formula and too little water will concentrate it, and either can undermine the nutrition your baby might otherwise receive.^{1, 2} This can also be very dangerous to your baby’s health.²

Read more: How Much Formula Does Your Baby Need?

How to prepare powdered infant formula

Powdered formula is most often prepared by using 2 ounces of water for every scoop of formula.⁷

1) Always add the water to the bottle first.

Prepare the water first if necessary. Remember to only use the amounts of water listed on the infant formula package instructions.^{2, 3}

**Note that it is recommended you prepare formula in even-numbered ounces only (for example, 2 ounces, 4 ounces, 6 ounces; and NOT 1 ounce, 3 ounces, etc). This is because you cannot get an exact half-scoop measurement of powdered formula, and you may end up over- or under- concentrating the formula.⁶

If you want 3 ounces of formula, make 6 ounces (6 ounces water plus 3 scoops formula) and split it into two bottles. Save one (or both) in the fridge until your baby is ready.

Read more: What Type of Water Can I Use When Preparing Formula and Should I Boil It?

2) Add the formula to the bottle second.

Tap the scoop lightly on the side of the canister to even it out or use a knife to scrape off the top. You don’t want to pack it down, but you also don’t want it overflowing.⁶ Only use the scoop from the container of formula you are currently using; each brand of formula may have a slightly different size scoop.³

How many ounces of water and scoops of formula needed to make infant formula:

If you want:	Use this many ounces of water:	Use this many scoops of formula:
2 oz of prepared formula	2 ounces	1 scoop
4 oz of prepared formula	4 ounces	2 scoops
6 oz of prepared formula	6 ounces	3 scoops

3) After capping the bottle, gently shake the formula until well-mixed.

Some formulas may be more sudsy or foamy than others, but this is normal. Feed to baby or refrigerate for up to 24 hours.

Batch preparation: Powdered infant formula

You can make up to 24 hours’ worth of powdered formula ahead of time. Each bottle should be prepared separately, covered, and stored in the refrigerator until your little one is ready. After 24 hours, the formula should be thrown out.

Special considerations for preparing powdered formula

• If your baby has special medical needs or is premature, your doctor or dietitian may recommend a different recipe for formula preparation.
• If you are mixing formula with breast milk, most of the time you prepare the formula first, then mix with the breast milk. Do NOT make formula using breast milk as the liquid, unless directed otherwise.

Have questions about formula preparation? Our Happy Baby Experts are registered dietitians and infant feeding specialists who can help guide you. They’re here to help on our free live chat from Monday – Friday 8am-8pm (EST), and Saturday – Sunday 8am-4pm (EST). Chat now!

How to prepare liquid concentrate infant formula

Concentrate formula is often prepared using a one-to-one ratio (equal amounts of water and formula).^{3, 7} But always make sure to read the directions on the side of the container of concentrate formula you are using to double-check preparation instructions.

1. Wash and dry the top of the concentrated infant formula can. Shake the can well before opening.
2. Pour concentrated formula into a clean bottle. If you would like a 4-ounce bottle, use 2 ounces concentrated formula and 2 ounces water.
3. Add the appropriate amount of water. Shake the bottle well. Feed to baby immediately or refrigerate for up to 48 hours.
4. Cover the concentrate canister and refrigerate for up to 48 hours.

Batch preparation: Liquid concentrate infant formula

You can batch prepare concentrate formula ahead of time, which you can then store in the refrigerator for up to 48 hours.⁶ Simply pour the concentrated formula into a clean and sterile storage container or pitcher, and then pour an equal amount of water in.⁷ Keep the container covered and use within 48 hours.⁷

Read more: Choosing the Right Formula for your Baby

How to prepare ready-to-feed infant formula

Ready-to-feed formula is the easiest option when it comes to formula; it is also the most expensive! These come in single-serve containers, usually in 2-, 6-, or 8-ounces; or a larger 1 quart (32 ounce) container.⁷

• Open single-serve bottle and attach the enclosed bottle nipple, or pour into a clean bottle. Feed to baby or refrigerate for up to 24 hours. OR
• Open larger 1-quart container, pour required amount into a clean bottle. Feed baby immediately or refrigerate bottle for up to 24 hours. Re-cap the ready-to-feed formula container and refrigerate for up to 48 hours.

Batch preparation: Ready-to-feed infant formula

You can separate out the large container of ready-to-feed formula into individual bottles to prepare for the day. Pour the amount needed into separate bottles, cover, and refrigerate until your little one is ready. These can be stored for up to 24 hours in the refrigerator.

Tips for storing infant formula

Storage tips for prepared formula 

• Powdered Infant Formula: One day’s worth (24 hours) of bottles can be prepped in individual bottles and stored immediately in the fridge in advance.
• Concentrated Infant Formula: Two days’ worth (48 hours) of bottles can be prepared and stored immediately in the fridge in advance.
• Do not freeze prepared formula.
• Prepared formula (that has not been given to baby yet) should not be without refrigeration for more than 2 hours.
• Once baby begins to drink a formula bottle, it must be used within 1 hour. Any remaining formula after the hour must be thrown out. ^{1, 2, 3, 7}

Storage tips for unprepared containers of powdered, ready-to-feed, or concentrated formula:

• Do not use formula past the “Use By” date on the container.
• Powdered formula can be used for one month after it has been opened. Manufacturers don’t recommend using the formula after the 30 days of opening because the nutrients start to degrade. Store powdered formula with the lid tightly shut in a cool, dry place – but NOT in the refrigerator.
• Open ready-to-feed or concentrate formula (unprepared) can be refrigerated for 48 hours. After this time it must be thrown out.^{1, 2}

If you can’t remember how long you have kept formula in the refrigerator, it is safer to throw it out than to feed it to your baby.

For more information, see the CDC’s formula preparation and storage instructions at: https://www.cdc.gov/nutrition/infantandtoddlernutrition/formula-feeding/infant-formula-preparation-and-storage.html

Let’s Chat!

We know parenting often means sleepless nights, stressful days, and countless questions and confusion, and we want to support you in your feeding journey and beyond.

Our Happy Baby Experts are a team of lactation consultants and registered dietitian nutritionists certified in infant and maternal nutrition – and they’re all moms, too! They’re here to offer personalized support on our free, one-on-one, live chat platform Monday – Friday 8am-8pm (EST), and Saturday – Sunday 8am-4pm (EST). No appointment needed, no email or sign-up required. Chat Now!

Read more about the experts that help write our content!

For more on this topic, check out the following articles:

Breast to Bottle: How To Transition

Feeding Tips for Healthy Weight Gain in Babies and Toddlers

What Do I Need to Know About Supplementing with Formula, Breastfeeding, and Pumping?

Should I Feed My Baby On Demand or On a Schedule?

Should I Switch Baby Formulas?