Best Breast Milk Storage Bag in 2020 [Buying Guide]

Last updated: July 12, 2020
Published 3:14 am

Lansinoh Breast milk Storage Bags

Dr. Brown’s Breast Milk Storage Bags

Kiinde Breast Milk Storage Twist Pouch

Published 3:14 am

Show Contents

Hide Contents

Content

Breast milk is the best source of nourishment for babies. They need breast milk to grow healthy. Breast milk contains nutrients that are often not found in formula. As such, it is best to feed your baby with breast milk. However, there may be cases where your baby isn’t with you, and you may wonder how to get the breast milk to your baby, this is where breast milk storage bags come into play. There are several benefits to using breast milk bags to store your breast milk.

You can pump and store your breast milk so that your baby can get all the nourishment they need, even in your absence. Breast milk bags design and construction make them able to store breast milk and keep it safe for your baby to consume. They are sterile and approved by the FDA for storing breast milk and freezing and thawing.

Have no idea what brand of breast milk bags to choose? Then this article is written for you. We have helped you review the best breast milk bags to help your buying decision making.

The 11 Best Breast Milk Bags Reviewed

1

Lansinoh Breast milk Storage Bags

Lansinoh breastmilk storage bags are a suitable storage bag for your breast milk; they can be frozen and will protect your breast milk. The bags are pre-sterilized and have a double zipper, which helps in preventing leakages, so you never have to worry about your breast milk wasting after expression. The breast milk storage bags are solid and reinforced with a double side seam.

The Lansinoh breast milk storage bags are free of BPA and BPS and are pre-sterilized; breast milk is safe for your baby to consume, and you never have to worry about sterilizing the bags before use. The bags are designed to lay-flat and enable the breast milk to freeze fast and thaw quickly too, which means the nutrients of the breast milk are well preserved.

You can pump breast milk directly into Lansinoh Breast milk storage bags to reduce waste and also have a pour spout. The bags also come with a write-on label so you can label your breast milk. The Lansinoh breast milk storage bags are very convenient to use and come as highly recommended breast milk storage bags to store nourishing breast milk for your baby.

Key Features:

  • Tamper evident tear away tops
  • Easy-to-write-on label
  • Volume measurement
  • Double zip seal
  • Reinforced double side seam
  • Pre-sterilized

Specification:

  • Brand: Lansinoh
  • Model: Lansinoh Breast milk Storage Bags
  • Count: 100
  • Volume: 6 ounces
Pros
  • The bags have a spout that reduces spills when transferring milk to bottles
  • Has a label for easy labeling
  • Is reinforced to prevent spills and leakages
  • Made from safe food-grade plastic that is free from BPA and BPS
  • You can pump directly into these bags
Cons
  • May sometimes break when thawing in warm water

2

Dr. Brown's Breast Milk Storage Bags

Dr. Brown’s Breast Milk Storage Bags have an extra-durable design that ensures your breast milk is always safe, and cushions the bags when dropped, which prevents them from breaking if they accidentally drop. The material used is food-grade and free from BPA. It helps keep your breast milk fresh. The bags come with a double zip seal, which keeps the air out to prevent the milk from going sour.

The top is perforated to make it easy to open; all you need to do is tear the top and gently pull apart the zip. The bags come pre-sterilized for immediate use.

The bottom of Dr. Brown’s Breast Milk Storage Bags is gusseted, which holds the bags upright. The bags are easy to label, so you can keep track of the freshness of the milk and put the name of your little bundle of joy.

Key Features:

  • Pre-sterilized
  • Double zip seal
  • Labeling
  • Gusseted bottom

Specification:

  • Brand: Dr. Browns
  • Model: Dr. Brown’s Breast Milk Storage Bags
  • Count: 100
  • Volume: 6 ounces
Pros
  • The bags are food-grade and made from very durable material
  • The labeling is easy to read
  • The double seal zip keeps breast milk fresh for long
Cons

3

Kiinde Breast Milk Storage Twist Pouch

The Kiinde Twist Pouch Breast Milk Storage for Pumping, Freezing, and Feeding are one of the best breast milk storage bags out there. Pump directly attaching a breast pump; this makes it very easy and convenient to use; it makes the process of storing your breast milk hassle-free. You can fit the bags into the Kiinde Squeeze natural feeding bottles to feed the baby directly from the pouch.

The breast milk storage bags have threaded caps, unlike ordinary zip milk storage bags. The threaded caps prevent leaks and ensure that you can transfer your breast milk safely without any worry of leaks. The Kiinde breast milk storage bags have measurement markings so you can measure the amount of milk your baby is taking.

The Kiinde Twist Pouch Breast Milk Storage for Pumping, Freezing, and Feeding are pre-sterilized, which saves you time sterilizing before use, and ensures that the milk is safe for consumption by your baby and minimizes contamination.

You can collect, store, and feed on the same pouch. The bags are self-standing, and lay-flat in the freezer to save space. The design of the bags makes the milk freeze rapidly and also thaw quickly too. The bags are made from recyclable material and are environmentally friendly.

Key Features:

  • Direct pump
  • Threaded Caps
  • Pre-sterilized
  • Measurement marking
  • Self-stand and lay-flat design

Specification:

  • Brand: Kiinde
  • Model: Kiinde Twist Pouch Breast Milk Storage for Pumping, Freezing, and Feeding
  • Volume: 6 ounces; 8 ounces
  • Count: 20, 40, 80
Pros
  • Comes in multiple sizes
  • You can pump directly
  • Leak-proof design with the threaded caps
  • Dual-layer material for durability
  • Enable feeding, storage, and collection in the same pouch
Cons
  • Takes up too much space and does not lay-flat

4

Medala Breast Milk Storage Bags

The Medala Breast Milk Storage Bags are made from highly durable material, and is constructed in double layers, and also with a built-in double zip. The dual zip protection prevents leaking, so your breast milk is safe in the bags to be stored in the freezer or during travels.

The breast milk storage bags are ready for use and are pre-sealed to ensure your breast milk doesn’t get contaminated. The bags have a self-standing design and are also designed to lay-flat to save space. The food-grade breast milk storage bags allow rapid thawing of the milk so you can feed your hungry baby almost immediately they are hungry.

The Medala Breast Milk Storage bags have a large area where you can write date and time you expressed the milk, your baby’s name, and any other relevant information you want to include. The bags come with a re-sealable transport pouch where you can keep the milk bags to prevent them from being contaminated, and also helps you to organize.

Key Features:

  • Double-layer material
  • Double zip protection
  • Self-standing design
  • Lay-flat profile
  • Transport pouch

Specification:

  • Brand: Medala
  • Model: Medala Breast Milk Storage
  • Count: 100
  • Volume: 6 ounces
Pros
  • Made from a dual-layer material, which makes it very durable
  • Breast milk thaws fast
  • Has a dual zip to keep milk fresh
  • The design is leak-proof
  • The bags are self-standing
  • Comes with a bonus transport pouch to keep bags clean and organized
Cons
  • It is a bit hard to pour milk into the bag

5

NUK Seal N' Go Breast Milk Bag

The NUK Simply Natural Seal N’ Go Breast Milk Bags are a pre-sterilized breast milk storage bag that comes in handy for lactating mothers. NUK breast milk storage bags are well known and have been around for a while now, and they help save milk for your baby when you are not around.

The NUK Simply Natural Seal N’ Go breast milk storage bags are self-standing and can freeze without you being afraid that they will bursts. NUK guarantees you the bags are 100% leak-proof and have a double zip seal with an oxygen barrier that keeps the milk fresh. The bags are food-grade plastic and BPA free and, as such, are safe for babies’ breast milk.

The bags also lay-flat in the freezer to save space; there is volume marking on each bag so you can know how much milk is in each bag. Also, the bags have an area where you can label and put in vital information. The NUK Simply Natural Seal N’ Go breast milk storage bags have a gravity-fed spot for easy pouring, and it prevents spills. The bags come in 25, 50, and 100 counts depending on your need.

Key Features:

  • Self-standing design
  • Pre-sterilized
  • Double zip seals
  • Volume marking
  • Label area
  • Gravity-fed pour spout

Specification:

  • Brand: NUK
  • Model: NUK Simply Natural Seal n’ Go Breast Milk Bag
  • Count: 100
  • Volume: 6 ounces
Pros
  • The bags are leak-proof
  • Double seal zip with an oxygen barrier to keep milk fresh
  • Gravity-fed spot, which prevents spillage and makes pouring easy
Cons
  • Regular pens may not write well on the bags

6

Ameda Store N Pour Breast Milk Storage Bags

Ameda Store ‘N Pour storage Bags makes the whole process of collection, storing, and pouring your breast milk very easy. The bags are very durable and sturdy due to the multi-ply design, which prevents the bags from cracking or splitting.

You can pump directly into the Ameda Store N Pour Breast Milk Storage Bags by using flange adapters. It is convenient to transfer into bottles. The bags feature a unique pour spout, which helps you prevent spills. The bags have re-sealable zips, which are easy to close.

The Ameda Store N Pour Breast Milk Storage Bags are pre-sterilized and are BPA free food-grade plastic. It means the bags are safe for your baby. The bags are freezer safe; they are designed not to break when frozen.

Key Features:

  • Pour spout
  • Multi-ply material design
  • Freezer safe

Specification:

  • Brand: Ameda
  • Model: Ameda Store N Pour Breast Milk Storage Bags
  • Count: 30
  • Volume: 6 ounces
Pros
  • The bags are very sturdy and can freeze without splits or cracks
  • Pour spout helps prevent spills
  • You can pump directly into the bags
Cons
  • The bags don’t seal properly
  • The measurement is not very accurate

7

Philips AVENT Breast Milk Storage Bags

Philips AVENT Breast Milk Storage Bags are very sturdy and safe breast milk storage bags. The bags are pre-sterilized to ensure the safety of breast milk you’re giving your baby. They are food-grade BPA free plastic, which is a must for breast milk storage bags. The storage bags are leak-proof thanks to the secure double zipper.

The Philips AVENT Breast Milk Storage Bags feature a tamper-evident seal so you can immediately tell if the bags have been tampered with, which means the tampered bags are not safe to be used to store breast milk. The bags are reinforced at the seams to prevent them from splitting, and they are also a dual-layer bag, which gives it the extra sturdiness.

Philips AVENT Breast Milk Storage Bags are very easy to use; the bags open wide for easy pouring. The bags are also self-standing.

Key Features:

  • Self-standing design
  • Pre- sterilized
  • Food-grade and BPA free plastic
  • Double zip
  • Labeling area

Specification:

  • Brand: Philips AVENT
  • Model: Philips AVENT Breast Milk Storage Bags, Clear
  • Count: 50
  • Volume: 6 ounces
Pros
  • The bags are leak-proof
  • Very durable as it has reinforced seams that prevent splits and leakages
  • Has a tamper-evident seal
  • It opens wide for easy pouring and reduces the risk of spills
Cons
  • The measurement may not be accurate
  • They don’t lay-flat

8

Milkies No Breaks No Leaks Breast Milk Storage Bags

Milkies No Breaks No Leaks Breast Milk Storage Bags are breast milk storage bags that were designed by mothers. These bags are very durable, with the sides reinforced, a double zip enclosure that prevents leaks. Even when frozen, the bags hold up and don’t break.

The bags are made from food-grade plastic and are free from BPA and are pre-sterilized for immediate use. The Milkies No Breaks No Leaks Breast Milk Storage Bags are self-standing and easy to fill. The bags have a flat freeze design that makes them take up less space in the freezer compared to some breast milk storage bags. The bags feature ounces and millimeter measurements on them and an area for you to label your breast milk.

Key Features:

  • Self-standing design
  • Reinforced seams
  • Double zip enclosure
  • Pre-sterilized
  • Lay-flat design
  • Measurement and labeling area

Specification:

  • Brand: Milkies
  • Model: Milkies No Breaks No Leaks Breast Milk Storage Bags
  • Count: 50
  • Volume: 6.5 ounces
Pros
  • The bags are very sturdy due to the no leaks and no breaks design
  • Have reinforced seams
  • The bags are pre-sterilized, which means it is ready for use instantly
  • The self-standing design makes pouring easy
Cons
  • The zipper may be a bit difficult to open

9

GLAND Breast milk Storage Bags

GLAND Breast Milk Storage Bag is designed with an Easy Pour Spout BPA free, and are CPSIA compliant. The bags are pre-sterilized and safe for immediate use. The bags come with a double ziplock, which protects the breast milk inside. The bags feature a pour spout, which aids transfers and makes them smooth, reducing wastage.

The GLAND breast milk storage bags are self-standing and have reinforced seams, which are double-sided sealed. The bags are to be compatible with the majority of breast milk pumps, meaning you can pump directly into the bags. Pumps speed up the process of collecting and storing breast milk to feed the baby. The bags have a perforated top that is easy to tear off for sanitation. The bags can lay flat in the refrigerator, which saves you space. The bags are leak-proof and safe for use in freezers.

Key Features:

  • Self-standing
  • Easy to pour spout
  • Dual zip lock
  • Pre-sterilized

Specification:

  • Brand: GLAND
  • Model: GLAND Breast milk Storage Bags Easy Pour Spout
  • Count: 100, 200
  • Volume: 8 ounces
Pros
  • Supports majority of breast pumps
  • A pour spout for simple pouring and reduces spills
  • Reinforced double seams, which prevent the bags from breaking
Cons
  • The bags don’t freeze flat
  • The measurement is inaccurate
  • The mouth doesn’t stay open when pouring
  • Despite the bags labeled as self-standing, it doesn’t stand well.

10

Mommy's Precious Breast Milk Storage Bag

Mommy’s Precious Breast Milk Storage Bag are pre-sterilized, BPA, and PHTHALATE free food-grade storage bags. The bags are leak-proof, so you don’t have to lose any of your precious breast milk; they are also self-standing. The bottom of the bags is also gusseted, which makes for easier single hand handling.

The pre-sterilized bags feature accurate measurement and tabs with the essential information areas on which you can write for easy labeling. The tear area is designed with a perforated line so you can open the bags easily in a neat and straight edge. The bags are designed by caregivers and take into consideration what every caregiver would want in a breast milk storage bag. The Mommy’s Precious Breast Milk Storage Bag freezes flat in your fridge.

Key Features:

  • Gusseted bottom
  • Pre-sterilized
  • Accurate measurement
  • Dual zipper lock
  • BPA and PHTHALATE free

Specification:

  • Brand: Mommy’s Precious
  • Model: Mommy’s Precious Breast Milk Storage Bag
  • Count: 55
  • Volume: 8 ounces
Pros
  • The bags freeze flat
  • The bags can stand on their own for easy handling
  • The measurement is accurate compared to other bags
Cons

11

TDWOW Breast milk Storage Bags

TDWOW Breast milk Storage Bags are very reliable breast milk storage bags that use a dual sealing to keep your breast milk fresh. Just a little pressure is applied to seal the bags, and the bags can be laid flat or upright. The milk inlet and outlet are separate to prevent breast milk from being contaminated. The seal is easy to tear because of the incisions made on it.

TDWOW Breast milk Storage Bags features a leak-proof pour spout. The edges are anti-crack edge technology, and the bag has no borders and corners as everything is smoothed out. On the bag, there is a Nursing Essentials area dedicated to storing information such as the date of the breast milk. The breast milk storage bags are free from BPA, which makes them safe for storing breast milk in them.

The base of the TDWOW Breast milk Storage Bags is broad, which makes it able to stand after being filled with milk. One of the great things about this milk bag is that the manufacturers claim to replace leaking bags unconditionally according to the product page.

Key Features:

  • Leak-proof pour spout
  • BPA free
  • Double sealing
  • Separate inlet and outlet for milk

Specification:

  • Brand: TDWOW
  • Model: TDWOW Breast milk Storage Bags
  • Count: 110
  • Volume: 8 ounces
Pros
  • The inlet and outlet are separated to prevent the milk from being contaminated
  • Has an Essential Nursing panel where you can add information
  • Can stand on its own
  • Milk doesn’t leak when thawing
Cons
  • The pour spout doesn’t rip, and you may need to use a scissors

12

DiRose Breast Milk Storage Bags

DiRose Breast Milk Storage Bags are pre-sterilized breast milk storage bags that are exclusively designed for the collection, storing, and freezing of breast milk. The bags are leak-proof and a dual zipper seal. DiRose Breast Milk Storage Bags have a pour spout to help reduce spills and a record tab on the top where you can write down any information. The side seams are reinforced.

The plastic used to construct the bags is thick, food-grade, and free of BPA. The bottom is not gusseted, and instead, it is rounded.

Key Features:

  • Pre-sterilized
  • Food-grade plastic free of BPA and BPS
  • Measuring guide
  • Record tab

Specification:

  • Brand: DiRose
  • Model: DiRose Breast Milk Storage Bags
  • Count: 50, 100
  • Volume: 6 ounces
Pros
  • The side seams are reinforced to prevent breaks or leaks
  • Has a measurement guide
  • The bag comes with a tab for you to record vital information
Cons
  • You can’t pump directly into the bags

Buying Guide Questions

We have reviewed the best milk storage bags and have gone in-depth into the various features, pros, and cons. This section is dedicated to the questions you may have. Read and find answers. Also, we have included a couple of tips for you; we hope they are useful to you on your breastfeeding journey.

Does it matter what breast milk storage bags you use?

Various brands make breast milk bags, and they come in different sizes too. They are made from different materials and the way they are designed. They all serve the purpose of the safe storage of breast milk. However, some somethings differentiates them in terms of design and features. These differences impact the performance of the bags and how reliable they are.

Several things must be considered when you are shopping for breast milk bags. You should ensure to store breast milk in the best breast milk bags available because you are saving the source of food for an infant whose body isn’t acclimated to the world around. Store your precious breast milk in a manner that is safe for the baby to consume.

The breast milk bags must be food-grade plastic. It is the most important thing you have to consider as a parent, and you want to be sure that the breast milk is safe for your baby to consume. Breast milk bags are free BPA, and BPE, dyes, additives and are chemical resistant.

Breast milk bags come with a tamper-proof seal to prevent the bags from being exposed, which will lead to them being contaminated and unsafe to hold milk for babies. Also, the bags avoid leakages and spills due to its design.

How many breast milk storage bags do I need? How long do they last?

The number of breast milk bags you need depends on various factors. On average, you may use about six bags every day. However, the volume of the bag also matters, some bags are more significant in size than others, and usually, the bags are between four and six ounces. However, there are larger ones too. Factor in leaks also, so you might want to have about two or three extra.

Ultimately the amount of bags you will need depends on how much your baby consumes, so be sure to note how much your baby consumes every day. You may keep extra bags in case of emergencies. Keep a few in your office, car, and pumping bags because you may need them at any time.

When you go on a trip, you may need as little as five depending on the length of the journey. Keep extra ten bags factoring leaks and breaks.

When storing milk for your baby, you may freeze enough to last your baby for months at a stretch; all these depend on you, how much milk you can produce and how much space is available in your freezer.

Can I use sandwich bags or regular freezer bags to store breast milk?

Use a breast milk storage bag to store your breast milk. Avoid using sandwich bags as they can not hold breast milk. They are more susceptible to leaks and may even split when frozen. Use unique breast milk freezer bags to store your breast milk instead of regular freezer bags.

Using breast milk storage bags are a great way to store breast milk, and they come with a couple of benefits. Sandwich bags don’t offer the same level of protection for your breast milk as the breast milk storage bags do. The bags are very thick and durable and are often pre-sterilized.

The breast milk bags often come with milliliter and ounce markings to make measuring the amount of breast milk in bags very easy for you. You can conveniently measure how much breast milk you are storing and how much you’re feeding your baby.

Breast milk storage bags thaw faster than any other type of bag. It is easy to label breast milk bags. There are different ways you can store your breast milk asides using breast milk bags or freezer bags. You can put it in glass containers or food-grade plastic containers that are BPA free.

There are many reasons why you may want to store your breast milk, whether you are not going to be around to feed your baby, or maybe your breasts feel full, and you feel uncomfortable, or any other reasons. You extract your breast milk though expression and store.

There are three different ways to express: by hand, by using a manual breast pump and using an electric breast pump. After expression, the milk is stored in breast milk storage bags or sterilized containers and then put into a refrigerator or freezer.

You should store breast milk in breast milk storage bags as it will save you time cleaning bottles you might have used instead. Breast milk bags are backups that come in handy if you have a hungry baby, and you forgot their bottles, or maybe you dropped it, or there are not clean bottles available. Whatever the reasons, breast milk bags are convenient backups.

You can’t use Ziploc bags for breast milk storage. An alternative to breast milk storage bags is to express in bottles.

Why can’t you reuse breast milk storage bags?

Breast milk storage bags are for single-use; after that, they are not suitable for use. It is because they are sterilized for single-use, and they may begin to leak after use, or they don’t seal properly. The upside to this is that they are reasonably cheap to buy, and some are recyclable.

To get the most out of your one use storage bags, it is essential you appropriately use them. Follow these steps to accurately and adequately use them:

Wash your hands properly. You’re handling what your baby would eat, and you need to maintain the maximum of hygiene to for the safety of your baby

Express by hand or use a pump. The choice is yours, go for anyone you are comfortable with.

Pour the milk into the bag carefully to avoid spills. Remove air in the bag, then seal it.

Freeze the bags if you want to store the milk for a very long time, or refrigerate if it will be consumed in a few hours to keep the milk fresh and full of nutrients.

Do not wash and reuse breast milk storage bags. Also, it is almost impossible to sterilize the bags again. If you are worried about running out of bags quickly, then buy in excess. You may opt to use bottles to keep your breast milk instead, but they are not as versatile as breast milk storage bags as the entire bottle of milk has to be consumed or disposed of.

Can you store breast milk in bottles with nipples?

Do not store milk in bottles with nipples still attached. Cap the bottles tightly after filling with milk and refrigerate. Before storing breast milk in bottles, ensure you sterilized the bottles properly. Clean them correctly and follow the recommendations of the manufacturer on how to clean them. Ensure the bottles don’t contain BPA and are food-grade. If you are in doubt, go for breast milk storage bags.

Can you combine breast milk from 2 different days?

You can combine breast milk from different days. However, you must never add warm milk to frozen or refrigerated milk. Make sure you refrigerate the warm milk first or cool it down before adding it to the other frozen or chilled milk.

Breast milk can be stored for a varying amount of time and is safe for consumption based on various factors. These factors include room temperature, freezer or refrigeration temperature, the time when you pumped the milk, volume, and so on. There are recommendations, however, on how to store breast milk and how safe it is to consume.

Freshly pumped breast milk at room temperature can sit for up to four hours, after which it should you throw it out. If you refrigerate it, it can stay for up to four days if Frozen breast milk can last up to a year.

Thawed breast milk must be consumed within two hours if it is at room temperature, or you throw it away. Thawed breast milk can be refrigerated, but must be consumed within a day if it has not stayed for up to two hours. Thawed breast milk must never be refrozen. To melt the breast milk, bring it out of the freezer, and let it stay in the refrigerator for about 12 hours. To speed up thawing, run cold water over the container and increase the water’s temperature gradually to keep the breast milk nourishing. If you want to warm the milk, heat water into a small box and place the thawed milk in it.

If you have leftover breast milk in a bottle from feeding your baby, the milk must is to be consumed within two hours, or you dispose of it. You must never feed your baby leftover milk from the same bottle.

You may notice that your breast milk has varying color, and you are wondering if it has gone bad. Breast milk may have the following colors: white, yellow, cream, tan, clear or have a blue ting. All these are normal and no cause for alarm. The color can be influenced by what you eat, and you can have a slight green red or pink coloration, it doesn’t mean the milk is bad.

Conclusion

Breast milk bags help you have a stash and steady supply of breast milk for your infant, even when you are not there. Traveling should not hinder you from storing breast milk in bags, just get an insulated box with ice to keep the milk cold. It can last you for a day after, in which the milk most be disposed of.

Below are some things you need to keep in mind.

Freezing breast milk immediately after the expression is the way to keep the breast milk fresh and of excellent quality. Freeze the milk bags flat so that you can save space in your freezer. Always label the breast milk storage bags with the date and possibly the time you filled them with breast milk. Do not keep the bags near the door of the fridge as the temperature will vary every time it opens. You want to maintain an even and cold temperature. Leave some space in the bags to cater for expansion when the breast milk freezes.

Do not microwave breast milk because microwave doesn’t heat up evenly. It creates pockets of hot liquid that may scald your infant. Also, a microwave is not suitable for heating breast milk because it may damage the nutrients.

Never shake breast milk; it causes the protein structure to break down as it is not strong enough to withstand such force. Instead, gently swirl the breast milk container if you notice layers in the milk when you want to feed your child. If your breast milk smells sour despite you storing it well, throw it away; it has gone bad.

Remember always to check your pumps and take care of them appropriately. If you notice mold in your breast milk pump tubing, replace it immediately.

If you want to know whether your breast milk has gone bad, a sniff can be an excellent indicator, although it is not very accurate. Inspect the stored breast milk, usually, when you save breast milk, it separates, and the fat rises, while the water goes to the bottom. Give the mix a gentle swirl, if you see chunks of milk or fat floating about, or the milk doesn’t mix then it has gone bad.

You can taste the milk; if it tastes rancid or sour, then it has gone bad and should be thrown away. However, high lipase content can cause the milk to smell or taste sour when the milk is frozen. To confirm, freeze fresh milk for a few days, then thaw the milk. If it smells or tastes this way, then it is probably due to high lipase content.

Lastly, if you have concerns, see a doctor.