What Do I Need to Know About Preparing Formula for my Baby?

As a Newborn Care Specialist (NCS) and New Parent Educator (CNPE), I’ve often encountered parents who are seeking advice on how to safely and quickly prepare powdered formula for their newborn.

Safe and Simple Formula Preparation for your Newborn

As a new or expectant parent, you may be feeling overwhelmed with all the conflicting advice you’ve received. Do you desire evidence-based advice that is easy to follow? Continue reading to learn more about how you can safely, and efficiently, batch prep powdered formula using items you likely already have around the house.

Why Proper Formula Preparation is Important

Newborns under 2 months of age, those that are immunocompromised, or who were born prematurely are more susceptible to infection.

It is important to note that powdered infant formula is not sterile. Due to this, it is possible for bacteria to be present in the powder. Newborns under 2 months of age, babies that are immunocompromised, or those born prematurely are more susceptible to serious infection from this bacteria. It is important to follow a few simple steps to ensure any bacteria that is potentially present is killed during preparation. While you don’t have to continue following these recommendations after your baby outgrows these risk factors, it is safe to continue to do so if that is your preference.

What You Will Need

The good news is that you can use items you already have at home to prepare formula—no need to add to the growing list of items you need to buy for your baby.

Gather the following:

• Powdered infant formula—check the expiration date, storage guidelines and preparation directions listed on the container of formula.

• Clean/Sanitized glass pitcher, jar, or baby bottles— I prefer to batch prepare using a glass pitcher, but you can choose whichever option works best for you. If using a glass pitcher or glass jar, verify measurement markings are correct prior to preparing formula.

• Kettle or pot (and thermometer to verify temp)— An electric kettle can save precious time over boiling water on the stove top in a pot. It is also makes it easier to pour the water into your pitcher. Often, these electric kettles are fast and you can set the exact temperature of the water. Always verify that the temperature readings are correct to ensure that you are using water that is above 158°F (70°C) .

• Sterilized stirring tool— The CDC recommends shaking formula to mix (this reduces the risk of germs being introduced from a stirring tool). If using a pitcher that you’re unable to shake, you can mix with a clean/sanitized stirring tool.

• Sticky Note/tape and pen for noting the date and time of preparation— You will need to mark the date/time of preparation so you know when you need to toss any unused formula.

Steps for Safely Preparing Formula

The following takes into consideration the extra precautions recommended by the US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) for powdered formula preparation for newborns under two months of age, those that were born prematurely, or are immunocompromised. 

1. Clean the preparation area and wash your hands; make sure all items are properly cleaned and sterilized: Your hands or prep surfaces can contain bacteria. Cleaning these surfaces thoroughly will reduce the risk of contaminating the formula you are preparing. 

2. Boiled or Hot Water: When boiled, let the water cool for approximately 5 minutes, but no more than 30 minutes. The water should be 158°F (70°C) or more when mixing with the formula powder. This temperature is hot enough to kill harmful bacteria in the formula. You must follow this step even if you are using bottled or filtered water because you are heating the water to kill bacteria potentially present in the formula.

3. Mixing Formula: Pour the hot water into a clean, sanitized glass bottle or pitcher. Next, add the correct amount of formula powder. You should measure the water first, so that your measurements are precise. Powdered formula will cause displacement and your mixed amount will be slightly more than the amount of measured water. Mix thoroughly. You can shake or use a sterilized stirring tool. 

4. Storage: Immediately after preparing, cover the pitcher and place it in the refrigerator. You can also pour prepared formula into bottles for storage. Formula can be stored safely in the fridge for up to 24 hours. If using immediately, be sure to cool the formula before feeding it to your baby.

5. Labeling: Use a post-it note and a pen to note the time you prepared the formula. This helps you keep track of when the 24-hour window is up. Any formula leftover after 24 hours must be thrown away.

It is recommended that you store milk on a shelf, preferably towards the back of the refrigerator. Storing it in the door exposes it to warmer temperatures when opening and closing the refrigerator door.

Feeding Prepared Powdered Formula

• Warming Up Formula: It is safe to give your baby cold formula. If your baby does not like it cold, you can try warming it enough so that it is cool, but not cold. This will offer you more flexibility when in a hurry or traveling and it is harder to fully warm the bottle prior to feeding. Never use a microwave as it can heat unevenly and create hot spots that could burn your baby. Instead, you can use a bottle warmer or place the bottle in a mug of hot water to gently warm it.

• Freshly Prepped Formula: You can use freshly prepared formula (as long as you haven’t started feeding it) within 2 hours of preparation.

• Feeding Time: Once you’ve started a feed, formula should be used within one hour. After that, any leftovers should be tossed out to prevent bacteria growth.

Preparing powdered formula according to the CDC and WHO recommendations might seem daunting at first, but with these simple steps, you can do it confidently, knowing you’re providing the best for your baby.

Seeking additional rescources? The CDC has more information on the extra precautions for formula prep and about Preventing Cronobacter in Infants. The WHO also provides a downloadable guide for safe preparation, storage and handling of powdered infant formula.

Disclaimer: The information provided in this blog is intended to offer general guidelines for safe formula preparation based on CDC and WHO recommendations. Depending on the brand of your formula, the specific instructions regarding water temperature or batch preparation may vary. If your formula specifies the need for use of a different temperature of water, or recommends against batch preparation, please follow the directions on your formula.

For more tips on caring for your newborn, or to see a formula prep demonstration, check out my Instagram or Facebook page! You can also sign up for a personalized consultation or a group class at kelset.com/classesconsults