IN THIS ARTICLE – Understanding how to safely prepare and store formula for your baby can be a little intimidating, but we've got you covered.
Medically reviewed by a board-certified pediatrician
There are different guidelines for powdered formula, ready-to-use and concentrated formula. We'll start with these three simple steps and then branch out into other instructions and information. Prepping your baby's bottle will become second nature in no time.
How to Make a Baby Bottle: How to Make Baby Formula Steps
- Step 1: Wash your hands
The first step to making baby formula is to wash those hands! Always. Make sure you do it thoroughly with soap and water. You want to avoid any unwanted germs when it comes to making your baby’s formula.
- Step 2: Measure water into bottle, add formula powder
The precise ratio of powder to water varies from formula to formula. Ask your doctor which formula’s best for you and follow the directions on the package. Also ask about using cooled, boiled water for mixing and boiled clean utensils, bottles, and nipples before feeding.
- Step 3: Tighten cap and shake
Mix well, then place a drop on the inside of your wrist to check the temperature. The liquid shouldn’t feel warm or cool—room temperature is perfect. Then it’s ready to serve.
How to make a bottle of Ready-to-Use formula
If you're feeding your baby Enfamil Ready-to-Use formula you need only wash your hands thoroughly, shake the bottle well, remove cap and attach the nipple (not included) to serve.
How to make a bottle of Enfamil A.R.™
If you're using Enfamil A.R.™, formula for spit-up, wash your hands thoroughly, measure out your powder and add it to the water. Cap the bottle and shake it well, let the bottle stand for five minutes, then shake it again before serving. This type of formula contains rice starch and is a little thicker than regular formula, so it needs a bit more mixing.
Don't be concerned if Enfamil A.R.™ appears grainy: this is normal for formulas with rice starch. If your bottle nipple is clogging, try swirling the bottle gently before serving, or using a nipple with a larger hole.
Baby Formula Guidelines
It's important to pay attention not only to what you are feeding your baby, but also how you feed them. Many new parents wonder, “How long does baby formula last?” and “How do I store formula?” When it comes to formula, there are multiple missteps you can make. Learn how to safely store and prepare baby formula, including powder, concentrate, and ready-to-use baby formula with the guidelines below.
Should you warm formula?
Formula does not need to be warmed. If you want to, place the bottle of prepared formula in a container of warm (not boiling) water, or run it under the warm tap for a little while. Always test formula by placing a drop on your wrist to make sure it isn't too hot.
Never to use a microwave to heat formula. Microwaves can heat liquid unevenly, resulting in hot spots that could seriously burn your baby, and may not be detectable when you test it on your wrist.
Should you add more water to make formula go further?
No. Follow the preparation directions on the package of formula. These amounts of water and formula are designed to provide your baby with the nutrition they need. Adding too much water to powder or adding water to liquid formula can dilute important nutrients.
Can you use bottled or filtered water to make baby formula?
Boiling the water first is safest. However, if you're traveling with your baby you can use Enfamil® Water, which is commercially sterile and ready to be mixed with formula. If you have concerns about lead or other harmful substances in your tap water, talk to your doctor about viable alternatives.
How do you make formula bottles in advance?
Mix concentrated liquid or powder formula with cool water (35 to 75°F); it should feel cool on your wrist. If you prefer, you may mix with warm water, but only if you plan to feed or refrigerate the formula immediately. Warm water is about 100°F or body temperature; it should feel neutral (neither warm nor cool) on your wrist. Powder should be added to the water and not vice versa since this can make a difference in the formula’s mixability and consistency. If you still have questions about prepping your baby’s bottle, follow the three easy steps above, and it will become second nature in no time.
How long is formula good for after mixed?
Once the powder formula has been mixed with water, you can refrigerate it at 35° to 40°F for no longer than 24 hours before feeding.
How long can formula stay out?
Baby formula that has been prepared from powder, concentrate, or opened ready-to-use should not be kept at room temperature for longer than a total of 2 hours. If the bottle has been warmed or feeding has begun, discard the formula after 1 hour.
Does formula go bad after an hour?
Yes. Prepared and warmed formula from powder, concentrate, or opened ready-to-use should be fed to your baby within 1 hour of being warmed, or it should be discarded. Do not refrigerate or save for later feedings.
Why is formula bad after an hour?
When formula that has been warmed and/or fed remains at room temperature for 1 hour, bacteria normally present in an infant's saliva will grow quickly in the nutrient-rich formula.
What happens if baby drinks old formula milk?
If you believe your baby has drank old formula, we recommend reaching out to your doctor to discuss any issues your baby may be experiencing. Your baby’s doctor is your best resource to determine what may be going on with your little one.
Can formula be reheated?
No. Re-heating formula increases the possibility of bacteria growth in the formula as it cools off after heating. Once the formula has been warmed for your baby, it cannot be refrigerated for later feedings.
How long does unopened formula last?
All formulas have an expiration date on the packaging. To find a formula’s expiration date, look at the top or the bottom of the container for embossed printed type with the date. For ready-to-use infant formula, look on the side of the label.
How long does powder formula last?
If unopened, you can follow the expiration date on the powder formula packaging. Once opened, the container’s contents need to be used within 30 days. Meanwhile, store the powder at room temperature in a dry area, with the lid tightly closed.
How long does Enfamil Ready-to-Use formula last?
If unopened, you can follow the expiration date on the Enfamil Ready-to-Use packaging. Once opened, the formula can be refrigerated for up to 48 hours.
Can you mix vitamin D drops with formula?
Yes! If your doctor has recommended vitamin D drops for your baby, you can mix the recommended amount in with your baby's formula. It may help disguise the taste of the drops and be easier for your baby to accept vs. using the dropper to dispense it into their mouth.
Now you know
Before you know it, you'll be a pro at preparing and storing baby formula. When someone asks, ‘’How long is baby formula good for?” you’ll answer without hesitation. Become even better at feedings by learning about formula-feeding and feeding issues you might encounter.
Updated on 09/13/2022