Pumping isn’t really what the stock photos on the internet and lifetime movies make it out to be. Sometimes it’s a full bottle in ten minutes, and other times it’s a small amount that barely covers the bottom. Fluctuations are totally normal, so there’s no need to worry!
Getting a consistent milk supply can take a little while.
Plus, breast milk output changes based on a number of things. It can vary depending on the time of day, hydration, stress levels, the frequency of milk expression, and several other factors. That said, it makes sense why some sessions give you a full feed while others only squeeze out a snack.
But here’s where the mental gymnastics tend to kick in: what do you do with those little bits of milk? Can you combine breast milk from different pumping sessions? And most importantly, is it safe? Good news, that’s exactly what we’re talking about today!
As rewarding as pumping may be, these small questions can begin to make you overthink. But instead of just saying “don’t worry, mama!” we’ll explain whether or not you can combine milk and how to safely do so. Nobody wants to waste that liquid gold!
Can You Combine Breast Milk From Different Pumping Sessions?
The short answer is yes! You can absolutely combine milk from different pumping sessions as long as you follow the correct guidelines. The main thing to remember is that your freshly expressed milk will still be warm, while the milk in the fridge is probably already cool. And if you pour warm milk straight into cool milk, it can raise the overall temperature and impact both safety and quality.
Ultimately, this can encourage bacterial growth and reduce the length of time it’s safe to collect and store your milk. Here are the golden rules:
- Cool first, then combine: Before you mix breast milk from different pumping sessions, chill it first. This allows you to safely combine both milks without sacrificing safety.
- Stick to the 24-hour rule: You can combine breast milk pumped within the same 24-hour window. After that, you should freeze it or use it.
- Use the correct storage method: If you’re combining frozen breast milk, the freshly pumped milk still needs to be cooled first, then frozen separately. Take the guesswork out of preparing your baby’s bottle with our milk storage cheatsheet!
So yes, it’s a bit more work than just pouring it together. However, it’s one of the most important steps in ensuring the safety of your milk.
How To Combine Breast Milk From Different Pumping Sessions
Knowing what you know now, how do you actually combine breast milk from different pumping sessions without wasting time, space, or any of your liquid gold? Here are the steps:
Chill your fresh milk before combining.
Always put your freshly expressed breast milk into the fridge to cool before mixing it with refrigerated breast milk. This helps keep everything at a safe temperature and preserves the quality of the milk. Even a small amount of warm milk can raise the temperature of your stored milk, encouraging bacteria to grow.
Use it within 24 hours at most.
If you decide to store your breast milk in the fridge rather than the freezer, use it within 24 hours. And make sure that you start that 24-hour time based on the oldest milk in the batch. So if you pump at 8 AM and again at 2 PM, once you mix them, you have until 8 AM the next day to use it safely.
Label it correctly to keep track.
When you combine breast milk, label the container with the date and time of the first pumping session. That way, you don’t lose track of how long it’s safe to use. And if you have expired breast milk on your hands and aren’t sure what to do with it? Check out our post, “What To Do With Expired Breast Milk.”
Be careful with frozen milk.
If you want to combine with frozen breast milk, you’ll need to thaw the frozen bag first (see how to thaw breast milk in bag). Then, once both are cool, you can confidently combine them. Make sure to never pour freshly pumped milk straight into frozen milk. This runs the risk of partially thawing the frozen portion, which can lead to spoilage.
How To Store Breast Milk From Different Pumping Sessions
Once you’ve figured out how to combine your milk from different sessions, the next step is ensuring you store it correctly. Here’s what you should keep in mind:
Use Proper Containers
Store your breast milk in BPA-free bottles or breast milk storage bags specifically designed for freezing and refrigerating. Avoid using any random food storage containers, as they are not always the safest or most sterile option for freezing.
Follow The Guidelines
Freshly expressed breast milk can be left at room temperature for about 4 hours. However, this should be done on a must-needed basis—like if you aren’t near a refrigerator or freezer. Ultimately, though, the goal is to avoid leaving it out whenever possible.
Refrigerate Quickly
Once pumped, you’ll want to pop your milk in the refrigerator to cool. You can technically use it within 4 to 7 days, but the earlier the better. Also, always place milk in the back of the fridge where the temperature is coldest and more stable, not in the door where temperatures fluctuate.
Freeze If Needed
If you know you won’t use the milk within 24 hours, freeze it. Frozen breast milk can safely last from 6 to 12 months. However, make sure to leave a little room at the top of the bags or bottles since breast milk expands when it’s frozen.
Handle Carefully
Once thawed, you should use the expressed milk within 24 hours. Breast milk should never be refrozen, so if it’s not used within the timeframe, it’s best to toss it. If you’re unsure about the process, visit my guide, “How Many Times Can You Reheat Breast Milk?” for some insight!
Combining breast milk from different sessions? Go for it!
Pumping is already tricky enough—you don’t need to waste time worrying if you’re “doing it wrong” when it comes to storing your breast milk and feeding your baby. That being said, yes, you can combine milk from different pumping sessions. The trick is making sure that everything is cooled thoroughly, stored properly, and labeled correctly.
Think of it this way: you’re not just storing milk. You’re storing hours of your time, energy, and literal tears. Every drop matters, whether it’s a small amount or a full bottle! And with the right support, you’ll save space, reduce waste, and feel confident in your pumping journey.
If all of this still sounds a little overwhelming for you right now, know that you don’t have to figure it out all by yourself. That’s why I created The Ultimate Pumping Course, along with supportive 1:1 consults, and tons of freebies! I want pumping to feel less like a mystery and more like something you can manage.
Because at the end of the day, you deserve to feel empowered—not stressed—about providing for your little one. Even if the pumping journey isn’t exactly what you pictured at first.
