What Happens If Baby Drinks Spoiled Formula Milk

Are you wondering what happens if baby drinks spoiled formula milk? You wake up late in the night to prepare a formula feed to give your baby, you are still half-asleep and you feel like something is not right.

Sniffing the feeding bottle you then realize that your baby has been drinking spoiled milk. Panic sets it. What to do? Worry not! Everything is going to be alright. No one is above mistake after all.

Therefore in this article, we are going to discuss what happens if baby drinks spoiled formula milk, what you can do if your baby drinks spoiled milk, and practical ways to prevent feeding your baby spoiled formula milk. We’ve got you covered!

What Is Old Formula?

According to a report by pediatricians and mothers all over the world, any formula milk that is fed to the baby after about 2 hours of its preparation is considered to be old or spoiled. There are two reasons behind this theory.

Firstly, when a formula is left open for a long time, it gets spoiled because of a bacteria know as Enterobacter Sakazakii. This is a naturally occurring bacteria that settles in dry food such as herbs, powdered milk, and baby’s formula.

In the department of infant health, many studies have been carried out to prove that these bacteria are very dangerous and also can turn fatal for newborns with existing medical conditions, whose immune system hasn’t been developed fully.

How To Know If Formula Has Gone Bad?

If you do not know whether or not your baby’s formula has expired, it’s best advised to err on the side of caution. If you feel it’s getting old or spoiled, avoid feeding it to your baby and throw it out at once!

To prevent foodborne diseases when serving your baby formula, you must practice good hygiene. Always remember to wash and dry your hands before preparing your baby’s milk.

Also, make sure to look out for signs of milk spoilage. When the formula starts to go bad, you should notice:

  • The smell will have an off aroma
  • Clumping
  • Separation of ingredients in the formula
  • Your baby might refuse feeding through her bottle or get sick after feeding

Read Also: What Happens If Baby Drinks Hot Formula

What Happens If Baby Drinks Spoiled Formula Milk?

baby fed spoiled formula milk

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


After your baby drank spoiled formula milk, the first thing you’ll notice is vomiting and some diarrhea.

Vomiting is a means through which your baby’s system tries to get rid of the spoilt food. Some babies may develop a fever after vomiting while others may settle and recover.


If your baby drank spoiled formula milk, her body will want to detoxify itself through Diarrhea. The Baby’s system passes the spoilt food differently than vomiting.

Both these processes cause weakness and dehydration in your baby and can affect her feeding pattern.

You must note how frequently your baby vomits and give him some water to rehydrate or see a doctor immediately.

Read Also: 13 Best Formulas That Taste Closest To Breast Milk

How Long After Drinking Spoiled Milk Will Baby Fall Sick?

Babies will often experience nausea on the first to the second day after eating contaminated food with a spoiled chemical.

Milk left at room temperature or allowed to sit in direct sunlight usually result from bacterial toxins found in their rancid flesh.

If you accidentally fed your baby spoiled formula, your baby may likely experience vomiting, diarrhea, and fever. All these symptoms are likely to occur for one to two days.

What Happens If Baby Drinks Spoiled Formula Milk: 5 Tips To Prevent Infections

Parenting is simply an art. If your baby is less than two years old, you must be very watchful because this is the time when she is growing up and her immune system wouldn’t be as strong as you would want it to be.

The best way to keep your child healthy and happy isn’t in suddenly switching from formula feeding to breastfeeding but in taking the right measures regardless of what feeding method you are using. Measures that may help include:

1. Sanitize Everything Used In Preparation And Storage

It isn’t much you can do about the bacteria because it occurs naturally and settles on surfaces. However, maintaining proper hygiene helps to prevent contamination of your baby’s food.

Sanitize every feeding parts you used to prepare and store your baby’s meals. Also, sanitize all pump parts before and after use if you pump breast milk.

2. Try Using The Liquid Formula

The bacteria Enterobacter Sakazakii which is a naturally occurring bacteria that settles in dry food seems to adhere to powdered products more than liquids.

This indicates that using liquid formula milk reduces your baby’s chance of getting infected by the bacteria.

However, the liquid formula must be kept according to the manufacturer’s guidelines and must be tightly sealed.

3. Don’t Warm In The Microwave

Warming your baby formula before feeding is unnecessary. However, if you intend to warm the milk formula or bottle, microwaving it is not your best idea.

This method does not warm food evenly which leads to different patches of temperature variation throughout the meal which can encourage bacterial growth.

4. Take Precautions During Preparation And Storage Of Formula

Make sure the formula milk lid is properly sealed in storage and cover the lid immediately after scooping what you need to prepare a meal.

Also, the water you use in preparing the formula must be clean or has been boiled and cooled before use. Always feed your baby within two hours of preparing the formula milk and throw away the leftover at once.

5. Make Sure Your Hands Are Clean!

Remember to wash your hands with mild soap and water immediately after using the toilet or changing your baby’s diapers.

Make sure you wash your hands before preparing the formula or making contact with anything that will touch your baby’s mouth like the feeding bottles and pacifiers.

Read: Enfamil NeuroPro Vs Gentlease- Which one is the best?

5 Practical Ways To Help Prevent Your Baby From Drinking Old Formula

formula milk

1. Always Label Your Formula

To prevent your baby from drinking old formula, label the formula bottles. Just like you would with expressed breast milk, write the date and time at which the formula was prepared.

This keeps your partner or caregiver updated on which one to use first to prevent infections and wastage. This trick guides your caregivers to feed your baby the older formula before the new ones.

2. Discard Old Formula Immediately  

Throw away any old formula immediately as this can prevent someone else from feeding it to your baby unknowingly.

There are guidelines on how long prepared and refrigerated formula milk can last. Studies from parenting moms and pediatricians have shown that by maintaining the right temperature, formula milk can remain viable for twenty-four hours.

3. Keep The Formula Away From Contaminants

As a nursing mother, it is necessary to devise a good method for proper formula storage. Anything that has the potential to make your baby fall sick if ingested should be kept at a distance from the place you prepare the formula.

A typical example of this is an old formula. Baby’s first few months are very critical to them, especially one with an existing condition, so be vigilant with whatever touches your baby’s mouth.

4. Be Observant

Formula milk can become infected even before it expires through contamination of the bottle or formula before preparation.

As soon as your baby starts acting strange or becomes less active accompanied by a fever or vomiting, see the doctor immediately. 

5. Avoid The Blame Game

Parenting can be rewarding and beautiful but sometimes it can be overwhelming and exhausting. Feeding your baby old formula can result in self-blame or blaming your partner. Unfortunately, that does not solve the problem.

Rather than blaming your partner identify what you both did wrong, seek counseling and direction from professionals, and work on doing better in the future.

Read Also: Best Formula To Keep Baby Fuller Longer

Other FAQs

How Long Is Powdered Formula Good Once It Is Opened?

Most big brands of infant powdered formula last for about a month after opening. Remember that if you buy an organic variety of powdered formula, the powder might go bad earlier depending on the ingredients.

Always go through the brand of your infant formula for their recommendations, and when in doubt, discard any infant formula that’s been open for more than a month.

What To Do With Expired Baby Formula

While it may be tempting to use your expired formula, well, it’s recommended not to use it to avoid putting your child’s health at risk.

If you don’t feel confident in discarding the formula because you bought it expensively, you can try to take it back to the grocery store and ask for a refund.

If your formula is still sealed, some grocery stores will let you exchange it for a new can. Return policies often vary by store, so be sure to check your particular store’s policy and do not forget to keep any applicable receipts.

You can also donate your expired formula to an animal shelter if the formula isn’t too far past its shelf life, and the spoilage isn’t too bad.

Another interesting option for what to do with your expired infant formula is to use it in gardening. It also works for food that’s contaminated and has gone past its best before date.

Can a Baby Fall Sick From Drinking Sour Milk?

There’s a good chance that your baby will not fall sick when he/she drinks spoiled milk.

If you accidentally fed your baby spoiled formula, your baby may likely experience vomiting, diarrhea, and fever but is unlikely to be hospitalized for such an issue.

Can I Feed My Baby Milk that is a Little Sour?

Yes, you can feed the milk to your baby if the milk doesn’t have an unpleasant smell or taste.

Related Posts:


As parents, it is common to make mistakes and as rewarding and beautiful as feeding your baby may seem, you must know good formula milk storage recommendations, and also understand the variances in milk appearance, smell, and taste of fresh formula milk as this can help prevent unnecessarily throwing out good milk.

More so, since a baby’s immune systems are weak, it’s very important to take the right measure when preparing your baby’s formula, because some infections can lead to death.

If there is any old formula remaining, you should throw it immediately so that you or your partner would not make the mistake of feeding it to your baby.

We do hope you found this article “What Happens If Baby Drinks Spoiled Formula Milk” helpful? If you have any formula milk gone bad stories or extra tips on how to prevent milk from going bad? Let us know in the comments section.