What Happens If Baby Drinks Spoiled Breast Milk

Mother’s milk is the best choice for babies as it contains nutrients needed for the baby’s growth and development. As a breastfeeding mom, storing breast milk is something you must do, regardless of whether they’re pumping all the time or just building up an emergency stash.

However, in some situations, that breast milk you’ve spent so much time pumping and storing can be bad for the baby. If you are a mother who wonders, “What happens if baby drinks spoiled breast milk”, then go ahead and find the answers.

Read on to learn all about breast milk, understanding how breast milk looks, smell and taste and also what happens if baby drinks spoiled breast milk.

Understanding The Way Breast Milk Looks

Normally, breast milk comes in a rainbow of colors and some of these colors are;

  • Yellow
  • Off-white
  • Blue-tinged
  • Slightly orange

The color of breast milk can even vary within the same pumping session. Much of the variance is due to the specific ratio of foremilk (thinner and more watery) to hindmilk (thicker and more fatty), and this tends to change from morning to night.

However, other things like diet, medication, herbs, and hydration play a role, too. The important thing is that there is a wide range of “normal,” and a change in color of your breast milk does not automatically make it bad.

Understanding The Way Breast Milk Smell And Taste

With regular dairy milk, the “sniff test” is usually the most accurate way to confirm whether or not the milk has spoiled. However, with breast milk, it’s usually not that easy.

The scent of breast milk is easily affected, so a strange smell doesn’t automatically mean its gone bad. It can also vary widely from woman to woman and can also change from day to day in the same person. Few things affect the smell of breast milk and they are:

  • Food.
  • Medications.
  • Freezing process.
  • Storage containers.

More so, because smell and taste are so closely linked, the same factors that affect your milk’s smell can also affect its taste.

A mother’s diet is an especially significant factor whereby a “spicy” taste or pungent spices can tinge a woman’s breast milk with that flavor.

What Happens If Baby Drinks Spoiled Breast Milk?

What Happens If Baby Drinks Spoiled Breast Milk

The first thing to do is to figure out if your breast milk has gone bad. Sometimes moms may see their breast milk separating, but International Board Certified Lactation Consultant (IBCLC) Deborah Dominici of Babies’ Breast Friend says that fat separation in breast milk is completely normal and it is not an indicator that your milk has gone bad.

She also said that sometimes when a mom has higher lipase in her milk, and when her frozen breast milk is defrosted, it could have a soapy or metallic smell, but still will be safe to give to your baby.

Danielle Spradlin, Certified Lactation Consultant from Oasis Lactation Services, narrates that when breast milk becomes not so fresh, it has a bad taste and also smells bad, with a sour and dirty sock smell.

If you noticed that your milk hasn’t passed the smell and taste test, and you’ve fed it to your baby, Dominici says they will likely throw it up.

Very rarely will milk spoil if you follow proper breast milk proper handling and storage guidelines she explains. Although, occasionally this can happen and generally the result will be vomiting up the spoiled milk.

Read Also: Why Does My Breast Milk Taste Salty?

How To Check Whether Milk Is Spoiled Or Not?

Breast milk comes with immune-boosting antibodies and some essential nutrients for your baby’s cognitive and physical development. Even if you’re breastfeeding exclusively, many moms find it necessary at some point to pump and store breast milk for later feedings.

La Leche League, explains that breast milk stored in a bottle at room temperature (between 66 and 78 degrees Fahrenheit) stays fresh for up to 4 hours and is usable for up to 6 hours, while refrigerated breast milk stays fresh for 72 hours but is usable for up to 8 days.

Frozen breast milk can remain fresh for 6 months and usable for 12 hours. If you find yourself confused about freshness, these few simple tests below can help you determine whether your breast milk has expired.

Take A Close Look

Normally, breast milk naturally separates after pumping, with the fat rising to the top and the water falling to the bottom. When milk is still good and fresh, it easily mixes with a gentle swirl of the bottle.

However, if your breast milk remains separated or chunks float in it after attempting to re-mix, it is likely it has gone bad and it’s a good idea to toss it.

Read Also: Why Your Thawed Breast Milk Looks Grainy

Smell Your Breast Milk

If you’ve stored the milk in the refrigerator or at room temperature, the “sniff test” could be a good way to determine whether your milk has gone bad.


While differences in the smell are normal with breast milk, if yours smells bad or like sour milk, it has probably gone bad. This technique may not be reliable, though, if you’ve frozen your breast milk.

Breast milk contains an enzyme called lipase which breaks down fats for your baby. In mothers with high lipase breast milk, the enzyme can cause thawed breast milk to smell sour, even though it is still perfectly safe.

To check whether your milk tends to take on this scent, freeze a small amount of breast milk for 5 days, then thaw it, and then check the scent.

In the short period in which you’ll do this test, you can be confident your milk has not soured, and it simply tends to take on this smell after freezing but is still safe for your baby.

Furthermore, it’s worth noting that some babies will reject this milk. So, before you freeze large batches of milk, try to feed some thawed milk to your baby to see whether or not they will accept it. If they won’t, you can correct this issue by scalding your milk before freezing.

To scald your breast milk:

  • Heat your milk in a small pan.
  • Wait for small bubbles to form around the outside (approx. 180 degrees F).
  • Remove from heat.
  • Allow cooling.
  • Pour into containers and freeze.

Taste Your Breast Milk

Just like the previous “sniff test,” taste your breast milk. It will taste different than cow’s milk, but any flavor other than sour is acceptable.

If you store your milk in the refrigerator and it tastes rancid or sour, it has likely gone bad and you should not feed it to your baby.

In the case of frozen milk, see the steps above to know whether your milk tends to take on a sour (but safe) flavor upon freezing due to a high lipase. If this is not the case, and your milk tastes sour in one particular instance, throw away the milk as it has likely gone bad.

Signs That Indicate That Mother’s Breast Milk Is Bad For Baby?

  1. Failure To Gain Weight: Breastfeeding babies should ideally gain between ½ kg to 1 kg every month for the first six months. If this isn’t happening, it is a certain sign that breast milk is bad.
  2. Frequently Upset: If your baby frequently seems ill-tempered, it could be that he isn’t getting the necessary nutrients from breast milk.
  3. Change In Bowel Movement: Once breast milk starts, your baby will produce at least 4-5 dirty diapers daily during his first six weeks.
  4. Fewer Diaper Change: 6 wet diapers a day on average for newborn babies. If you feel this number has dropped, it could be a breast milk-related issue.
  5. Delay In Reaching Milestones: If your baby’s milestones like rolling over, crawling, or sitting up are delayed, it could be a sign of deficiencies related to breast milk supply.
  6. Dark Colored Urine: If your baby urine color is dark, it shows that your baby isn’t getting essential fluids that can be supplied through breast milk.
  7. Always Sleepy: Newborn babies can sleep for up to 17-18 hours a day in slots of 3-4 hours each. If your baby seems sleepy and lethargic all the time, this could be a sign of intolerance to mother’s milk.
  8. Dissatisfied Feeling: A nursing session should leave a baby satisfied and calm. However, if your baby isn’t receiving enough quantity or if the right nutrients in the milk are missing, it’s likely your baby may cry for more.
  9. Signs Of Dehydration: Your baby may show signs of dehydration if he is not getting enough fluids and there could be several reasons for this.
  10. Increase In Gas: If your baby is drinking more of watery foremilk, this could cause excess gas.
  11. Short Feeding Sessions: Always monitor your feeding sessions to know if they are becoming progressively shorter. Naturally, your baby should be feeding at each breast for 10 minutes.
  12. Body Swelling: If your baby is facing problems with breast milk, you will notice swelling around his face and stomach areas.
  13. Odd Colored Stool: Your baby’s stools should be yellowish in color and mushy in consistency after you start breastfeeding him. When his stool changes to bright green with a frothy texture, this indicates low-calorie intake from breast milk.
  14. Allergic Reaction: Some breastfeeding babies can have allergic reactions to their mother’s milk. The type of food the mother eats could be one of the reasons for this. Some common signs of breast milk allergy include excessive gas, vomiting, diarrhea, and increased irritability.
  15. Growth Stoppage: Apart from not been able to gain weight, if your baby hasn’t grown in length, it could also indicate some issues with breast milk.

Read Also: How To Store Formula Milk For Night Feeds

6 Useful Ideas For Expired Breast Milk


Breast milk is a good skin softener and may help with minor blemishes. Stir in a little at your baby’s bath time, or relax in your milk bath.

To make it extra relaxing, mix with some fresh herbs or essential oils. This is recommended for milk that is just past best storage practices (never use moldy milk).

Freeze It

Store your breast milk in the freezer into cubes to treat minor cuts, scrapes, and bruises. Not only will the cold help to reduce swelling and inflammation, but breast milk has incredible healing properties. Make sure it’s label correctly so it is not mixed up with milk intended for consumption.


Another approach to enjoy milk during bath time is by making homemade soaps. Amazon has some extraordinary soap-making kits, similar to the custom melt and pour soap-making kit, just stir in a little breast milk during the process.

Alternatively, there are a lot of great soap recipes available on Pinterest you can check out as well.


This one is my best choice. There are a lot of shops gifted to turn your expired milk into wearable art. Since the milk is not for consumption it doesn’t normally need refrigeration or a cold shipping process.

How cool would it be to have a souvenir of this special time in baby and mama’s relationship?

Sore Nipples

Sore nipples are usually common during the early day of breastfeeding. Expired or leftover breast milk can provide soothing relief and helps nipples heal faster. To do this, simply express some breast milk directly onto your nipple and allow it to dry to reap the benefits.

Diaper Rash

Research has shown that breast milk was just as effective as hydrocortisone in treating babies with diaper rash. To do this, simply pat some breast milk on your baby’s bottom and then allow it to dry putting the diaper back on.


Some infants develop baby eczema in the first couple of months. According to research, it was found that breast milk was equally effective in the treatment of eczema compared with hydrocortisone.

Here is a video showing you how to make DIY breast milk lotion

Read Also: How To Travel With Breast Milk

Other Frequently Asked Questions

How Long Does Breast Milk Sit Out Before It Goes Bad?

Here are a few points to know how long breast milk can sit out before turning bad:

  1. Freshly pumped mother’s milk can be kept at room temperature (around 25°C) for 5 to 8 hours before it goes bad.
  2. Breast milk that has been previously refrigerated can sit out at room temperature for a maximum of up to 4 hours.
  3. Frozen breast milk that is thawed, but is yet to be warmed up can stay out for up to 4 hours.
  4. Frozen breast milk that has been thawed and warmed cannot be kept at room temperature since it can go bad immediately.
  5. Frozen breast milk that has been taken out of the freezer cannot be stored or defrosted at room temperature at all.

How To Prevent Breast Milk From Going Bad

Here are a few practical ways to ensure that expressed breast milk doesn’t go bad:

  1. Use Right Storage Container: Use a clean bottle with the date marked and an airtight seal or a heavy-duty freezer bag. Do not use bottles with regular tops and plastic bags as they could leak or spill.
  2. Follow Storage Guidelines: If you have used an insulated cooler bag to store breast milk, ensure that it is used up within 24 hours. Refrigerated breast milk will not go bad before 5 days.
  3. Follow Freezing Guidelines: There should be a space of at least an inch between the container top and the milk to allow expansion while you freeze breast milk. Breast milk containers should be kept at the back of the refrigerator where it is the coolest.
  4. Thawing Rules Should Be Followed: Do not leave breast milk out at room temperature to thaw. Never have you refreeze thawed breast milk. Also do not attempt to thaw breast milk in the microwave or gas stove.
  5. Choose Quantity Rightly: Express milk according to demand and there won’t be too many storage hassles. Breast milk has an impact on the baby’s health if the mother’s diet is uttered. When breast milk is expressed and stored, there can be side effects if storing guidelines are not properly followed.

Read Also: Foods That Make Breast Milk Taste Good

How Long Can I Store My Breast Milk?

breast milk storage

For Healthy Full-Term Infants:

You can store it at room temperature for 6 to 8 hours (at no warmer than 77°F, or 25°C). Then in the refrigerator, you can store it for up to 5 days at 32°–39°F (0°–3.9°C).

In the freezer, you can store it (be sure to leave about an inch of space at the top of the container or bottle to allow for expansion of the milk when it freezes).

For up to 2 weeks in a freezer compartment located inside the refrigerator. For 3 to 6 months in a freezer that’s self-contained and connected on top of or on the side of the refrigerator and is kept at 0°F (–18°C).

Always store the milk in the back of the freezer, not at the door. For 6 to 12 months in a deep freezer that’s always -4°F (–20°C).

To thaw frozen milk, you can move it to the refrigerator (it takes 24 hours to thaw), then warm by pouring warm water over the bag or bottle of milk and use it within the next 24 hours.

However, if you need the milk immediately, remove it from the freezer and run warm water over it until it’s at room temperature. Do not refreeze it.

Once your baby starts to drink from the bottle, you should use it within 1 hour. You may also notice that different resources provide different variations on the amount of time you can store breast milk at room temperature, in the refrigerator, and the freezer. Do not forget to talk to your doctor if you have any concerns or questions.

Read Also: What Happens If A Baby Drinks Breast Milk With Alcohol? Find Out

How Much Milk Should I Store In The Freezer?

While some women may choose to pump large volumes to be frozen, it’s a good idea to store the breast milk in 2- to 4-ounce (59.1 to 118.2 milliliters) portions so as not to waste any.

Mark the bottles, cups, or bags with the date, and then freeze them. You can also pour the milk into ice cube trays that have been thoroughly cleaned in hot water, let them freeze until they get hard, store them in freezer bags, then count up the number of cubes needed to make a full bottle.

My Frozen Breast Milk Changed Color. Is It Bad?

Breast milk that’s been frozen might look a little different from fresh breast milk, but that does not mean it has gone bad.

It’s normal for early breast milk to look kind of orange and the mature milk to look slightly blue, yellow, or brown when frozen. It may also separate into a creamy looking layer and a lighter, more milk-like layer.

If this happens, just swirl it gently to mix it up again. Thawed milk may smell or have a soapy taste due to the breakdown of fats in the milk.

Don’t be worried, the milk is still safe to drink, and most babies won’t have a problem with it. But if your baby doesn’t like it, the milk can be heated to scalding (bubbles around the edges) right after it is pumped or expressed and then quickly cooled and frozen. This switches off the enzyme that breaks down the milk fats.

How Do I Clean Baby Bottles And Pump Parts?

Before your baby first uses, wash and then sterilize the nipples, bottles, and washable breast pump supplies by boiling them for 5 to 10 minutes. Also, check the manufacturer’s recommendations for the length of time to boil the parts.

More so, you can sterilize the parts with a countertop or microwaveable sterilizer, but boiling works just as well and costs nothing. Then wash the bottles, nipples, and pump supplies in hot, soapy water (or run them through the dishwasher) after every use. They can transmit bacteria if not properly washed.

Read Also: How To Lose Belly Fat While Breastfeeding


The first signals to stop feeding your child should be to stare at your squam or to refuse your food. Having worked so hard pumping your milk, you don’t want a drop to go to waste.

Therefore, it is important to know good storage recommendations, and also understanding the variances in appearance, smell, and taste of normal breast milk as this can help prevent unnecessarily throwing out good milk.

This is why it’s important to ensure that you feeding your baby won’t make them sick, and knowing how to test it for spoilage will do just that.

Do you have any breast milk gone bad stories or extra tips for testing spoiled milk? We’d love to hear in the comments section below.