p>With so many different ways to store breast milk, it’s easy to be confused. Should you use collection bottles or containers? How long can your refrigerate breast milk? When should you put the milk in the freezer? Can you combine frozen breast milk with freshly expressed milk? How do you keep all those bags of breast milk organized? Ahhh!!!
Here’s a simple guide that breaks it all down for you. You basically need to know:
- how long you want to store the breast milk until you’ll use it
- how much room you have in your refrigerator or freezer
- basic safety guidelines to thawing, reheating, and mixing breast milk
So here we go.
I’ve just expressed some fresh breast milk. How long can I keep it in a bottle at room temperature?
Freshly expressed milk can be kept out at room temperature for about 3-6 hours. This is assuming temperatures of around 65-80 degrees Fahrenheit. Make sure the milk is capped and kept out of sunlight or other sources of heat.
If the temperatures are hotter than this, then you should use the milk within 2-4 hours. You should discard the milk if you cannot use it within these time frames.
I have a cooler or ice pack. How long does breast milk last in a cooler?
If you’re pumping at work or while you’re traveling, then you probably have a cooler with ice packs with you. You will want to make sure that the cooler can maintain a temperature of under 65 degrees Fahrenheit until you can get the milk into a refrigerator.
The guideline for keeping expressed milk in a cooler is up to 24 hours, though 4-6 hours is more typical for working moms.
How long can breast milk be stored in the refrigerator?
Expressed milk can be kept in the fridge for 3-7 days. Obviously it would be best to use the milk as quick as possible as nutrients begin to degrade and bacterial spoilage begins after 3 days or 72 hours.
Keep the milk in the coolest spot in the fridge, this is usually in the middle shelf or near the back where the vents are. Do not place breast milk in the door racks or near the top shelf where your fridge lights are as these places fluctuate up and down in temperature each time you open the door.
How long can I freeze breast milk?
Freezing is the best choice if you want to build up a stockpile of milk for emergencies. If you cannot use your milk within a week after it is expressed, then it should be frozen.
Frozen milk can be used up to 6 months later before you begin to see problems with freezer burn.
Just like keeping milk in the refrigerator, you’ll want to keep your milk in the back or middle of the freezer where temperatures are the coldest and the most stable. Do not keep the milk near the door.
If you have a deep freezer, you should be able to store your breast milk for up to 12 months before it degrades noticeably. If you are exclusively pumping or stocking up a large supply of breast milk, you should consider getting a deep freezer. There are models like this one that are as small as a mini fridge. It’s better than taking the risk of tossing all your hard-earned breast milk due to a freezer not being cold enough.
Breast milk storage guideline chart
Containers for storing breast milk
You can either store your expressed milk in collection bottles or storage bags.
The brand of storage bottle you can use will depend on your breast pump, so check your manual!
Bottles are the easiest to use if you plan to feed your baby within a few hours, using a cooler, or only plan to store a couple bottles in the refrigerator. Since you express milk directly into the bottles, all you need to do is to screw on a cap and keep the milk somewhere cool until you’re ready to use it. There’s no need to worry about pouring, thawing, or mixing. You will want to use post-it notes to label each bottle with the date when the milk is expressed or have a system for lining the bottles up (first in-first out) so you don’t get confused about which bottle to use first. Or just use a bottle organizer like this, but then you’ll have another bulky gadget in your fridge. Hmm…
The downside to keeping your breast milk in bottles is that they are bulky and since liquids expand when frozen, they are prone to cracking if you freeze an overfilled bottle.
For longer term storage or freezing, breast milk storage bags are the best choice. Some bags are designed so that you can pump directly into them, but it is more likely that you will pump into a collection bottle and then pour the milk into the bag.
Breast milk storage bags are not reusable and should be tossed out once you thaw out your milk and pour it into a bottle at feeding time. Buy the big 100 bulk pack if you know you’ll be using these a lot. The savings will add up!
Storage bags can be kept flat and stacked together if you use an organizer, so they are perfect for saving space in your fridge or freezer. Label each bag with the date when the milk was pumped and stack them so that the oldest milk is at the front/top. You’ll have a neatly stacked stockpile of breast milk ready to grab and go.
Even though they won’t explode like overfilled bottles, you should be careful not to overfill storage bags as they can leak when you unfreeze the milk and let it thaw.
While storage bags are a great way to prevent freezer burn in breast milk and to save space, they are not environmentally friendly and the costs can add up if you have a large supply of milk in storage.
The most cost effective, waste free, and space saving way of freezing expressed milk is with a breast milk ice tray.
These trays are like large ice cube trays and each slot is made to store 1 oz of milk. You simply pour your expressed milk into the slotted tray, snap on the lid, and then pop the tray into a freezer.
The trays are not air-tight so you will want to move the milk cubes into a ziplock bag for long-term storage to prevent freezer burn. Remember to date the ziplock bag with the date of the oldest breast milk.
The frozen milk ice cubes are easy to use at feeding time. Just pop one or two into a bottle and use the bottle to thaw and warm the milk. The only disadvantage to milk storage trays is that you can’t pump directly into them, however this is also true for storage bags. You’ll also have to wash them in between each use.
How to thaw breast milk and the right way to use frozen milk
The right way to thaw frozen milk is to move the milk directly from freezer to refrigerator about 24 hours before you need to use it.
If you have poor time management skills (like me!), then you can thaw the breast milk under cold running water. Only do this for breast milk you plan to use immediately!
Warm up the thawed milk in a bottle warmer, not a microwave. Microwaving milk seems like a quick time saver, but it’s easy to end up with hot spots that could burn your baby’s delicate mouth! If you don’t have a bottle warmer, the old fashioned way to warm up a bottle is to place a bottle of milk standing up in a hot (not boiling!) pot of water for a couple minutes. Test the temperature of the milk on the inside of your wrist before feeding.
Can I mix freshly expressed breast milk with frozen milk? Can I mix milk from different days?
If you want to add fresh milk to already frozen milk for storage, you can do so. Just make sure to put the container back into the freezer right away and to label the milk with the date of the older milk first. The storage lifespan of the mixed milk is the lifespan of the oldest milk.
If you’re mixing fresh and frozen milk for feeding, then you will want to warm the milk back up to body temperature before you give it to your baby.
If you can’t use up all the thawed milk in one setting, you can put it back in the refrigerator for 12-24 hours. Toss out milk older than this. Do not refreeze thawed milk.
My breast milk looks separated and watery when it thaws?
This is perfectly normal. The milk and fat portion of your milk will separate after being frozen and the fatty cream will rise to the top. You just need to gently swirl (not shake!) the milk when it’s warmed and it will emulsify.
My milk is a funny color? What color should breast milk be?
You might find that your milk takes on a different color depending on your diet at the time. This is perfectly normal and there’s nothing wrong with the milk. Milk can have a yellow, blue, brown, or even green tint sometimes.
I’ve thawed my milk and it smells rancid or freezer burned.
This can happen if the storage container wasn’t air tight or if the milk was in storage for too long.
Throw out any breast milk that smells funny. Even though it might not be spoiled, most babies will not drink breast milk that is rancid or freezer burned.
Some people will produce breast milk that is high in the lipase enzyme. This is the enzyme that breaks down fats in your breast milk. High lipase levels in milk will cause frozen milk to go bad faster.
If you’re storing your milk correctly and not for a long time, then your problems may be caused by lipase. The only way to prevent milk spoilage is to lightly boil the milk before you place it into storage. This deactivates the lipase and prevents it from breaking down the milk. Let the milk cool to room temperature and put it into storage.
How much breast milk should I take out of the freezer and thaw each time?
Babies will eat around 2oz to 4oz of milk in a feeding. If you’re thawing out milk the day before, estimate the number of bottle feedings per day and place that amount of milk in the refrigerator.
If you’re thawing milk for use right away, only take out what you need for one feeding.
Does frozen breast milk lose nutrients?
Freezing is the best form of breast milk storage over long periods of time. Unfortunately, the process of freezing and thawing will affect the nutritional content of the breast milk.
While cold temperatures will slow down the process of degradation, fats and nutrients will still break down. That’s why it is recommended that you use up any stockpiles of breast milk within 6 months and to use up older milk first. Breast milk older than half a year should be tossed and your supply replenished. If possible, it is best to use up frozen breast milk within 3 months of being expressed.