What Every Parent Ought to Know About Safely Storing Breastmilk & Formula

This article is about safely storing breastmilk or infant formula for later use. This is a topic that not a lot of people will think about until they find themselves with some unused milk in their hands, and wonder: so do I just put it in the fridge? The counter? Toss it?

Luckily, someone else has already done this research 😉

Here are the guidelines to safely store milk for infant consumption, whether it be mommy’s breastmilk or formula milk.

Breast Milk Storage


To prepare to pump your breastmilk, first you need to have the right equipment. There are multiple breast pumps you can choose, but one of my favorite that I recommend for my new moms is the Spectra Baby Premier Electric Breast Pump (you can buy using our affiliate link) because it is powerful yet very comfortable, and has a super convenient closed system that protects from the machine from milk back flow that has ruined so many mom’s machines.

Second, you must always wash your hands with soap and water for at least 20 seconds before handling your breasts or the equipment. If you share a pump with someone else, make sure to wipe all the components that are shared such as the dial / button.


The first thing you should consider is storage amount. It is recommended that breast milk is stored in 2-, 3-, or 4-oz batches. This is to prevent any waste.


Once baby starts to drink from a bottle of stored breast milk, the rest should be used within the next 2 hours. If the remains are refrigerated right after the feeding, they can be used for the next feeding.

Room Temperature

If cleanly expressed, breast milk can be store at room temperature (up to 77 degrees Fahrenheit) for 4 hours. If extreme cleanliness was used at extraction, it can remain at room temperature for up to 6-8 hour (careful when pushing these limits!).


It is important to remember that the fridge can be subject to temperature variations due to the door opening and closing, so the back of the fridge is actually the area that will maintain the most consistent temperature. The refrigerator temperature you want is about 39 degrees Fahrenheit (or 4 degrees Celsius). This milk should ideally be consumed within the next 4 days, but 8 days is the absolute maximum time. When you are ready to feed, you can warm the milk the traditional way by putting it in a warm bath, or using a bottle warmer. The warmer I like to recommend is the Philips Avent Bottle warmer because it warms safely and evenly in under 3 minutes.


If you have some freshly expressed breast milk that you are not planning to use within the next 24 hours, it should be frozen and stored in the back of the freezer (more stable temperature). You can store the breast milk for up to 9 months in a freezer with a temperature of 0 degrees Fahrenheit (-18 degrees Celsius), like the freezers that come attached to a normal refrigerator but with its own door. If you have a deep freezer (or chest freezer) that chills down to -4 degrees Fahrenheit (-18 degrees Celsius), these can keep the milk safe for up to 12 months.


After thawing breast milk, it should be refrigerated and consumed in the next 24 hours. Breast milk should never be thawed in the microwave because it warms in uneven patterns and there is a risk of milk being hotter in some areas of the bottle than others, and scalding your baby inadvertently. To safely thaw milk, but the frozen milk in the refrigerator overnight or put it under running warm water (or a bowl of warm water). For thawed milk that needs further warming to the perfect temperature, you can use a bottle warmer like the Philips Avent bottle warmer I mentioned above. Test the temperature of the thawed milk by placing a couple drops of on your inner wrist.

Room temperature4 h, with a maximum of 6–8 h if very cleanly expressed
RefrigeratorUp to 4 d, up to 8 d if very cleanly expressed
Freezer (in a refrigerator with a separate freezer door)Up to 9 mo
Deep freezerUp to 12 mo

Formula Storage

Room temperature

A bottle of prepared infant milk formula can be kept at room temperature (up to 77 degrees Fahrenheit)  for up to 1 hour .

Refrigeration & Freezing

When your baby drinks from a bottle, the remaining content should not be saved for later and should be tossed after the 1-hour mark. If a concentrated or ready-to-feed formula is unused, then it can be saved in the refrigerator for up to 48 hours as described in the above section. Any unused formula prepared from powder, then that one can only be stored safely in the fridge for up to 24 hours (powder formula is not completely sterile).

Powder formula storage

Once you open a can of powder baby formula, it should be used within the next 30 days, then tossed.


That was a lot of information! Feel free to bookmark this page for reference. I hope you have learned something to help you store your baby’s milk safely.

Question time!  

What kind of milk does your baby drink? Leave your answer in the comment section below, I would love to hear from you guys.

If you like this post or if you know someone who could find it useful, please share with a friend! Also, find us on Facebook using the link at the bottom of the website, and like our page for the latest updates. You can also subscribe to our email newsletter to be informed first of our new blog posts.

This post uses affiliate links. As an Amazon Associate, I earn from qualifying purchases.
That means that we may receive commissions when you make purchases through our link, at no expense to you, to help support our website. This does not impact our reviews and comparisons. We try our best to keep things fair and balanced, in order to help you make the best choice for you. If you decide to use it, thank you for your support 🙂 (more info?)

Updates in Infant Nutrition. Dina M. DiMaggio, Amanda Cox, Anthony F. Porto. Pediatrics in Review Oct 2017, 38 (10) 449-462; DOI: 10.1542/pir.2016-0239

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.