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Can You Mix Breast Milk From Different Days – Explained

Can You Mix Breast Milk From Different Days - Explained

As I navigated the world of breastfeeding, I’ve often wondered about the possibility of mixing breast milk from different days. 

The notion of combining breast milk collected at various times seems practical. Will it retain its nutritional value? Is it safe for the baby? 

In this guide, I’ll explore whether or not it’s advisable to mix breast milk from different days. 

By examining the science behind breast milk storage, potential risks, and expert advice, I aim to help my fellow parents make informed decisions.

Is It Okay to Mix Breast Milk Pumped at Different Times?

I’m often left with small leftover quantities of breast milk collected from various pumping sessions throughout the day. I often ask myself if I can combine these batches.

EXPERT ADVICE: To ensure your baby’s nutritional requirements are satisfied when making the switch from breast milk to formula, speak with a pediatrician.

Can I Mix Breast Milk From Different Hours?

Can I Mix Breast Milk From Different Hours?

After choosing and using the best breast pump, it may seem like a waste not to use the leftover breast milk you’ve pumped. 

Whether it’s acceptable to mix breast milk pumped at different hours is a common concern among breastfeeding parents. 

The consensus is that mixing breast milk at different hours is safe and permissible. 

Breast milk has a distinct flavor that varies slightly from individual to individual but is frequently characterized as mild and creamy.

While there may be slight variations in the milk’s appearance, consistency, and nutritional content, it poses no significant risks to the baby’s health.

Can I Mix Breast Milk From Two Different Days?

Can I Mix Breast Milk From Two Different Days?

Whether it’s acceptable to mix breast milk on two different days is an important consideration for breastfeeding parents. 

Bottle feeding breast milk is common for parents who express and then store their milk for later use.

Mixing breast milk from two different days is generally not recommended. Each day’s breast milk composition can vary in nutritional content and protective properties. 

Mixing milk from different days may result in an imbalance of these essential components, affecting the overall quality of the milk. 

To ensure the best outcome, store breast milk from each day separately and use them in the order they were pumped. This practice helps the milk maintain an optimal nutritional value. 

By following these rules for your baby’s well-being, they can get the most nourishment possible from your breast milk without exposing them to potential hazards related to mixing milk.

NOTE: The number of wet diapers a baby has is a sign that they are getting enough breast milk. Typically, 6 or more wet diapers a day is a positive sign.

Can I Mix Fresh Breast Milk With Refrigerated Milk?

Can I Mix Fresh Breast Milk With Refrigerated Milk?

It’s safe to mix fresh breast milk with chilled milk.

Breast milk is good for up to 4-6 days when safely stored in the refrigerator, depending on proper handling and storage conditions.

Mixing these two types of breast milk is efficient and ensures that none of your breast milk goes to waste. However, there are several significant variables to think about:

  1. Firstly, let freshly pumped breast milk cool in the refrigerator for about an hour before combining it with refrigerated milk. This step helps bring the temperature of the fresh milk closer to that of the already chilled milk, minimizing any potential temperature variations that could affect the quality of the mixed milk.
  1. Secondly, it’s important to note that all the mixed milk should fall within the same safe storage time frame. Breast milk can be safely refrigerated for up to four days, so ensure that the kinds of milk you’re mixing are within this time frame to maintain freshness and safety.

When looking for sources to buy breast milk, consider reaching out to local hospitals or birthing centers that may have recommendations.

NOTE: Some parents mix breast milk and formula as a gradual transition method when introducing formula feeding to their baby.

How to Properly Store Breast Milk for Mixing

To ensure proper mixing, first ensure all the milk is stored at the same temperature, preferably in the refrigerator.

Investing in a dedicated freezer for breast milk storage will ensure the milk stays fresh for longer.

If you have freshly pumped milk that is still warm, briefly cool it in a mini-fridge for breast milk before mixing. It helps align the temperatures of the different batches, reducing the risk of temperature shock.

To get the optimal temperature for feeding, I advise learning how to warm up breast milk properly. Remember to also label each breast milk storage bag with the date and time of pumping. 

Following this procedure, you can monitor the milk’s freshness and adhere to the “first in, first out” principle when feeding your infant. You can confidently mix breast milk at different hours by sticking to these guidelines. 

Consult with a lactation specialist or healthcare professional for guidance tailored to your situation.

QUICK TIP: Ask breastfeeding support groups or online communities to learn how to breastfeed successfully. Breastfeeding has many benefits, like a lower incidence of breast and ovarian cancer in mothers. Breastfeeding extends beyond the baby’s health.

Frequently Asked Questions

If you’re still unsure about combining breast milk from different days, check out these questions for more information.

Can I Pump Into the Same Bottle All Day?

You can pump into the same bottle all day if you follow proper hygiene practices and refrigerate the bottle between pumping sessions. 

Label the bottle with the date and time of the first pumping session, and use the oldest milk first within a four-day storage period.

Can You Mix Frozen Breast Milk From Different Days?

No, mixing frozen breast milk from different days is not recommended. Each batch of frozen breast milk may have different nutritional compositions and storage durations.

Mixing them can result in an imbalance and affect the quality and freshness of the milk. It’s best to thaw breast milk and use each batch separately, following the recommended storage and thawing guidelines.

Can I Mix Fresh Milk With My Baby’s Leftover Milk?

Yes, you can mix fresh milk with your baby’s leftover milk. 

Combining the two is safe and acceptable if the leftover milk has been properly stored and remains within the recommended storage time frame. 

Mixing fresh milk with leftover milk helps reduce waste and ensures efficient use of your breast milk supply.


In summary, when it comes to whether you can mix breast milk from different days, it is generally advisable to store and use breast milk from each day separately. 

Mixing breast milk from different days may compromise its nutritional composition and protective properties. 

To ensure the highest quality and benefits for your baby, follow proper storage guidelines, label containers accurately, and prioritize a “first in, first out” approach. 

By maintaining good hygiene practices and seeking guidance from healthcare professionals or lactation specialists, you can confidently provide your baby with safe and nourishing breast milk while maximizing the efficiency of your milk supply. 

Remember, each breastfeeding journey is unique, so ask the experts if you have any specific questions, mama!

Nayna Llenos
Nayna Llenos

Hi, I’m Nayna!
I’ve always wanted to be a mother, and I’m lucky and blessed to have two wonderful children to care for and love.
Despite this blessing, there are times wherein I do wonder if I truly am the mother my children need. Am I giving them the right food, care, and discipline to them?
But that is the beauty of parenting — you grow along with your children as they flourish to be their wonderful selves!
I wish to share my experiences with motherhood and how these tips can help you in your parenting journey.
I hope my advices and experiences will prove useful to you and that you have a smooth and wonderful journey as a mother!