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How Much Breastmilk to Store Per Bag

How Much Breastmilk to Store Per Bag
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If you are pumping more milk than your baby eats, you probably are wondering how much breastmilk to store per bag.

Pumping and storing breastmilk is a time-consuming process that requires organization and attentiveness. Without these things, you risk wasting milk.

The best way to make sure you don’t waste milk is by storing smaller amounts of milk in each storage bag, so you don’t thaw too much milk at once. 

It is best to store 4 ounces of breastmilk in each bag, which is enough for a single feeding. Some moms store anywhere from 2 to 6 ounces per bag for different reasons. Since you can’t refreeze breastmilk, freezing more than you need in a bag is wasteful. As your baby gets older and needs more milk per session, you can begin to store larger amounts. 

Breastfeeding and pumping is a labor of love, so it is disappointing when breastmilk is wasted. Storing your breastmilk isn’t just as simple as putting 2 ounces in a bag and popping it in the freezer.

Below are more details about how to freeze and store breastmilk correctly, how to tell when your breastmilk has soured, and some alternative uses of breastmilk.

How to Freeze and Thaw Breastmilk

Most women who pump and store breastmilk will pump enough for the next day, but there are times that milk production is high. If you are pumping often and exceeding what your baby needs, you must have strong organization methods for your storage. 

How you store your breastmilk will depend on how much you are producing each day. 

  • If you are only pumping 2 to 4 ounces at a time, then storing and freezing in those increments would be the easiest for you.
  • If you are producing more than that, you can decide if you want to split up your milk into different serving sizes or freeze it in 6-ounce increments.

Once you thaw frozen breastmilk, you only have 24 hours to use it before it is no longer suitable for consumption. You cannot refreeze breastmilk, even if it was thawed in the refrigerator. Therefore, it is crucial to only freeze your breastmilk in amounts that you will be able to use within a day. 

If you were to store 4 ounces in each bag, you would be able to split that into two different feeding sessions before the 24-hour mark.

If you are fearful that you may not use the milk within 24 hours, you can mix it into the food your baby will eat or dump it in their bath that night to allow for an extra soothing bathtime.

The following chart tells how long it takes to thaw frozen breastmilk:

Child’s Age(in months)Ounces of MilkThaw in Refrigerator for:Thaw in Warm Water for:
0-22 ounces10 hours30 minutes
3-64 ounces12 hours30 minutes
6-126-8 Ounces12 hours45 minutes

(Source: CDC)

Note: Freezing breastmilk for storage is preferred because breastmilk will only last three days in the refrigerator, but it may last up to 12 months in the freezer. 

When you thaw breastmilk, you will notice a thick layer of fat on top of the watery breastmilk on the bottom. This is normal, and with a few gentle stirs, the fat will mix with the watery breastmilk.

The fat only separates because it is heavier than the rest of the milk and is not an indication of how old or new your breastmilk is. 

If there is not a layer of fat, this means that you are only pumping enough to produce the foremilk or the thin part of the milk that contains no fat. While your baby can still eat this, they do need hindmilk (the part of the milk that contains the fat) to help them gain weight and promote brain function.

If you start to pump right after a feeding session with your baby or extend your pumping session by 5 or 10 minutes at a time, you should start to see more hindmilk. 

How to Store Frozen Breastmilk

When storing your breastmilk, you want to keep it as organized as possible, so you always use the oldest milk first. This helps prevent milk from expiring before its used. It is crucial to find a storage system that works for you. 

Here is one way to keep your breastmilk organized in storage:

  • Lay each storage bag flat until it freezes. 
  • Once the milk has frozen, you can either stand the bags up or stack them on each other.  
  • Organize the bags from back to front, oldest to newest, so you always grab the oldest one first. 
    • Keep the bags grouped by month in labeled containers. 
  • If you have too many to store in one box, you can label the box with the date ranges its stores. Then, you can stack the boxes top to bottom, oldest to newest. 

If you need a container to store your breastmilk in, many options are rated for freezer use and have plenty of room for bags and milk. 

Any of these options should make storing your breastmilk much easier:

Has Your Breastmilk Expired?

If you are concerned that your breastmilk has spoiled or expired, there are a few ways you can tell if it has gone bad: 

  • Your breastmilk will smell like spoiled milk.
  • Your breastmilk does not mix correctly once thawed.
  • If you can’t tell after the first two tests, do a taste test. If it tastes like sour milk, it has spoiled. 

Remember that color is not a good indication of whether breastmilk has spoiled or not. Your milk can change colors depending on what you eat, the medicines you take, and what you drink. 

The most common colors of breastmilk are:

  • Red
  • Pink
  • Green
  • Blue
  • Orange

However, each person makes milk differently. What you ate can even affect the color of your breastmilk. If you are concerned about the color of your breastmilk, contacting a Lactation Consultant will help ease your concerns. 

How to Use Spoiled Breastmilk

You will inevitably end up with breastmilk that has expired – but you can still use it! While it isn’t wise to ingest it, as long as the milk is not moldy, the good bacteria and antibodies in breastmilk are still active enough to remedy some issues your baby might have. 

Expired breastmilk can be used in the following ways:

Option 1: Freeze breastmilk in ice cube trays and use it for minor cuts and scrapes.  The cold will help with the pain and swelling, and the breastmilk will help fight off infection and germs. 

Option 2: Use it in baths to help soothe and calm diaper rash, eczema, or other skin issues.  This can also be done for adults.

Option 3: Use it in homemade bar soaps for extra soothing properties. 

Option 4: Breastmilk can be used as eye drops if your baby has pink eye or another eye infection. 

Option 5: It can be made into breastmilk jewelry so you can commemorate your journey. 

Storing Breastmilk

Breastfeeding and pumping are great ways to bond with your baby, and the countless benefits it gives makes the time and lack of sleep more than worth it.

The way you store your breastmilk is a critical aspect of the entire process and can make or break your ability to create a milk stash. It is a good idea to store the oldest milk at the front, so you can grab it first before it goes bad. 

Next, Check Out:

  1. How to Pump Milk for Daycare
  2. How To Build A Breastmilk Stockpile
  3. 4 EASY Tips To Fix Low Milk Supply At Night

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How To Store Breastmilk Tips. Photo of frozen breastmilk in bags.


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