Skip to content

Newborn & Infant Care

How to Address and Prevent Bad Smells in Baby Bottles

Caregiver inspecting a clean baby bottle beside a mint drying rack and bottle brush.

If you’ve ever detected a foul smell from your baby’s bottle, you know how unsettling it can be. After all, you’ve cleaned them properly, so what’s causing the odour? In this guide, we’ll discuss how to eliminate bad smells from baby bottles and how to prevent them in the future.

At SleepBaby.org, we’re dedicated to providing expert advice on all things baby-related, from sleep patterns to bottle feeding. Understanding issues like bad-smelling baby bottles can help your baby have a more pleasant feeding experience, which may lead to better sleep as well.

Why Do Baby Bottles Smell Bad?

Several factors could cause your baby’s bottles to develop an unpleasant odour. Identifying these will help you clean the bottles properly and get rid of the smell:

  • Method of cleaning: handwashing or dishwasher
  • Recent switch in detergent brands
  • Leaving dirty bottles out for too long
  • Use of juice in the bottles
  • Frequency of sanitization
  • Age of your bottle brush
  • Type of bottle: plastic or glass

Are You Handwashing or Using a Dishwasher?

Whether you handwash your baby bottles or use a dishwasher, both methods can occasionally leave an unwanted smell. The key is to avoid washing the bottles with other dishes, especially if they contain grease or tomato-based foods. This residue can transfer onto the plastic bottles and leave a smell.

Have You Switched Detergent Brands Recently?

Changing your detergent can sometimes lead to an unwanted smell in the bottles. If you’re used to unscented or all-natural soap, a new detergent could leave a residue. Also, well water or hard water can react differently with certain soaps and leave a distinct smell.

Do You Leave Dirty Bottles Out for Too Long?

Leaving used baby bottles on the counter or sink for an extended time can cause them to develop a smell due to bacteria growth. Even a small amount of leftover milk can start to smell when absorbed by the plastic. Baking soda can neutralize odours—simply add a teaspoon to a clean bottle filled with warm water, shake for a minute or two, rinse, and clean again.

Do You Use Juice in the Bottles?

Some types of juice, like grape or apple juice, can leave a tint or smell on the bottles if not washed promptly after use. To prevent this, wash the bottles immediately after your baby is done drinking.

Do You Regularly Sanitize the Bottles?

Proper sanitization is critical to reducing odours. Plastic can absorb smells easily, but regularly sanitizing your baby bottles can help manage this. You can use microwave-safe sanitizing bags or boil the bottles in water for five minutes to kill any lingering bacteria and odours.

When Did You Last Replace Your Bottle Brush?

If your bottle brush is old or not cleaned properly, it could be the source of the smell. Clean your brush every other day in the dishwasher or microwave and replace it monthly to prevent bacterial growth.

Have You Considered Switching to Glass Bottles?

While plastic bottles are safe, especially BPA-free versions, glass bottles don’t absorb smells as much as plastic and are a more eco-friendly option. Glass bottles still require sanitization but are less likely to develop strong odours.

Identifying the Causes of Bad Smells in Baby Bottles

Why Do Baby Bottles Smell Weird or Bad Even After Washing?

Baby bottles can develop an odd or unpleasant smell even after washing due to various reasons. These include bacteria or milk residues left behind, use of certain soaps or detergents, or using unclean water for washing. A smell might also indicate the presence of mildew or mold in the bottles.

What Does Mold Smell Like in a Water Bottle?

Mold in a water bottle often produces a musty, stale odour. This is an indication that the bottle needs immediate thorough cleaning or may even need to be replaced.

Why Do My Baby Bottles Smell Like Dish Soap?

If your baby bottles smell like dish soap, it may be because the soap residue is left behind after washing. Rinsing the bottles thoroughly after washing can help remove this smell.

Why Does My Bottle Smell Like Rotten Eggs or Fish?

A rotten egg or fishy smell from your baby’s bottle may be due to bacteria or mold growth. It’s essential to deep clean and sterilize the bottle as soon as you notice these smells.

Eliminating Bad Smells from Baby Bottles

How Do You Get the Smell Out of a Bottle or Remove Smell from Plastic Bottles?

Bad smells can be removed from baby bottles by deep cleaning and sterilizing them. You can also use natural odour neutralizers like baking soda. For plastic bottles, it’s essential to ensure they’re thoroughly rinsed after washing to remove all soap residue.

How Do You Get the Musty Smell Out of a Bottle or Get Rid of Rotten Milk Smell?

Musty or rotten milk smells can be removed by cleaning the bottles with warm soapy water and then sterilizing them. Baking soda or vinegar can also be used to neutralize these odours.

How Do You Deep Clean Baby Bottles or Get Mold Out of Baby Bottles?

Deep cleaning involves washing the baby bottles thoroughly with warm soapy water, then sterilizing them either by boiling or using a sterilizer. If mold is present, the bottle should be cleaned with a bottle brush to remove the mold before sterilization.

Best Practices for Cleaning and Maintaining Baby Bottles

How Often Do You Need to Clean a Water Bottle or Baby Bottle?

Baby bottles should be cleaned after each use. If the bottle is used for water and the water is changed regularly, it should be cleaned at least once a day.

What Detergent is Best for Cleaning Baby Bottles?

A mild, fragrance-free detergent is usually best for cleaning baby bottles to avoid leaving any residue or smell. Baby-friendly detergents are also a good choice.

Is it OK to Just Rinse Baby Bottles?

Rinsing alone is not sufficient to clean baby bottles. They need to be cleaned with soap and water to remove milk residues and bacteria and then sterilized.

How Often Should You Replace Baby Bottles?

Baby bottles should be replaced every 4-6 months, or sooner if they show signs of wear and tear or if they remain cloudy or smelly despite thorough cleaning.

What Age Do You Stop Sterilizing Baby Bottles?

Sterilizing baby bottles can be stopped after the baby is 1 year old, but the bottles should still be thoroughly cleaned after each use.

Do You Need to Sterilize Baby Bottles Before Every Use?

It is recommended to sterilize baby bottles before every use for newborns and infants up to six months old. After that, it’s sufficient to sterilize the bottles once a day and clean them thoroughly after each use.

How Long Do Bottles Stay Sterile Once Removed from Steriliser?

Once removed from the sterilizer, bottles stay sterile for up to 24 hours if they are kept sealed in the sterilizer or if they are immediately assembled and sealed.

Are Cloudy Baby Bottles Safe and How to Clean Cloudy Baby Bottles?

Cloudy baby bottles may indicate soap residue or scratch marks which can harbour bacteria. They can be cleaned by soaking in a mixture of vinegar and water. If the cloudiness persists, it’s best to replace them.

How to Get the Smell Out of Baby Bottle Nipples?

Bottle nipples can be cleaned in the same way as the bottles themselves. Soaking them in a baking soda solution can also help remove smells.

How to Get Sour Milk Smell Out of Baby Bottles?

To remove a sour milk smell, clean the bottle thoroughly with soap and warm water, then sterilize. If the smell persists, try soaking in a baking soda solution.

How to Get Milk Residue Out of Bottles?

Milk residue can be removed by scrubbing with a bottle brush during cleaning. Soaking the bottles in warm soapy water before cleaning can help loosen stubborn residues.

Preventing Smelly Baby Bottles: Final Thoughts

Keeping your baby bottles smelling fresh is crucial not just for hygiene but also to ensure your baby enjoys their feeding experience. Regular, appropriate cleaning, prompt washing after use, frequent sanitization, and timely replacement of cleaning tools are all part of effective bottle hygiene.

At SleepBaby.org, we understand the importance of these small details in making your baby’s day (and night) comfortable, contributing to better sleep. Explore our resources for more valuable insights and tips on baby care.

A gentle bedtime path from Kacey Bailey

Your baby won’t sleep. Yet again.

You’re tired. You feel helpless—desperate to help your baby sleep. The SleepBaby Method gives you a gentle, science-informed approach you can follow without “cry it out.”

  • No cry-it-out
  • Newborns through toddlers
  • Instant digital access
  • 60-day guarantee
2:59 a.m.

You know this moment

You just woke up. For the third time tonight.

You feel like a zombie—more dead than alive. And yet, you need to get up because it hurts your heart to hear your baby cry.

Hi, I’m Kacey.

I’m about to show you a scientific approach to help your baby fall asleep. The SleepBaby Method is designed for newborns through toddlers and does not involve the controversial “cry it out” method.

Most notably, I am a parent just like you. My baby, Benjamin, refused to fall asleep and stay asleep. I understand how it pulls on your heartstrings when your baby won’t sleep.

Kacey sharing a tender, peaceful moment with sleeping baby Benjamin
Kacey + BenjaminThe reason SleepBaby began

The story behind the method

My baby wouldn’t even nap anymore.

When Benjamin was born, my husband and I were elated. We thought he was the cutest baby on planet Earth—and we felt even more fortunate because he was an incredible sleeper.

Then, when Benjamin turned five months old, things changed seemingly overnight.

Benjamin started waking hourly—or every three hours if we were lucky. The sleepless nights began showing up in our work, our patience, and even our marriage.

I went online desperately searching for a solution. I bought the books, the tapes, and even hired a sleep consultant who simply told us to let our baby cry it out. I knew I needed another way.

01

An incredible sleeper

At first, bedtime came easily and we felt like the luckiest parents in the world.

02

Everything changed

At five months, Benjamin began waking again and again throughout the night.

03

A gentler answer

Kacey worked to create a practical method that did not rely on leaving a baby to cry alone.

Try these tonight

3 gentle ideas when your baby won’t sleep

These are three of the safer sleep ideas Kacey shares before introducing the complete method.

A parent and toddler laughing together during a warm, playful bedtime moment
01

Unleash the Giggle Monster

Stress can play a big part in why a baby won’t settle. A little laughter can help release built-up tension—and it gives you a warm moment of connection before sleep.

A parent, child, clock, and flowing path from evening light into a calm bedtime
02

Adjust the Bedtime

A later bedtime does not always make sleep easier. When a child has been awake too long, an overtired “second wind” can make settling harder. A consistent, age-aware schedule can help.

A baby sleeping safely on their back in a clear crib while gentle sound waves float through the room
03

Noise Can Help

The right steady sleep sounds can help a baby feel calm and protected. The complete method includes a collection of sounds designed for baby sleep.

A faster way to help your baby sleep

What you’ll discover inside The SleepBaby Method

  • The most effective alternatives to nursing or rocking your baby to sleep.
  • Ways to help your baby feel loved instead of crying for extra attention at bedtime.
  • Simple ways to ease bedtime anxiety and help your baby arrive at sleep calmly.
  • Baby sleep schedules designed around your child’s age.
  • Holistic ways to support your baby’s natural sleep rhythms without drugs.
  • A complete collection of soothing baby sleep sounds.
Get Instant Access
A connected storybook path through six calm bedtime discoveries
One connected bedtime path—not another pile of conflicting advice.
The SleepBaby Method digital guide with Baby Sleep Music, Deep Into Dreams, and Sleepy Siblings
The complete four-part SleepBaby package

The complete method + all three bonuses

Everything you need to start a calmer bedtime tonight.

Get unlimited access to The SleepBaby Method, the practical guidance Kacey created after Benjamin’s sleep changed, and all three digital bonuses.

Instant digital accessOpen the complete method and all three bonuses on the next page.
  • Complete digital workshop and guide
  • Baby Sleep Music
  • Deep Into Dreams
  • Sleepy Siblings
  • 60 days to explore the complete method
Continue to Instant Access

Instant digital delivery · Start in minutes

Everything included with your access

Three bonuses for the nights that need a little more help

01
Baby Sleep Music bonus cover

Baby Sleep Music

A collection of sounds designed just for babies, created to support a calmer, more peaceful sleep setting.

02
Deep Into Dreams bonus cover

Deep Into Dreams

Simple steps to encourage happy dreams so your baby can sleep peacefully and undisturbed.

03
Sleepy Siblings bonus cover

Sleepy Siblings

Practical help for putting siblings or twins to sleep at the same time—whether they share a room or sleep separately.

In their own words

What parents shared with Kacey

Anna Olson

“I was insanely sleep deprived when I heard about you from my son’s daycare. No matter what I tried, my baby wouldn’t sleep and it was driving me crazy!”

“Your information is very intelligent, easy to follow, and unique.”

Anna OlsonTampa, Florida
Paul Deleon

“As a single dad, I am already tired and my baby’s sleep problems made it even worse.”

“Since starting your method, he now sleeps through the entire night. Thank you, thank you, thank you!”

Paul DeleonSydney, Australia
Diana Erickson

“Thank you for helping my baby finally sleep! We felt like we were having the worst time and felt so stuck.”

“My baby is now on a sleep schedule that makes her and I both much happier during the day.”

Diana EricksonBristol, England

These are individual parent experiences. Every child and family is different.

A parent and sleepy child sharing a warm hug inside a quilted moon-and-sun ribbon
60daysconfidence promise

A full 60 days to decide

Try The SleepBaby Method for a full 60 days.

Explore the complete method and all three bonuses for 60 days. If it is not right for your family, contact us and we will make it right.

No questions asked. You can begin tonight and decide with confidence.

See Your Instant-Access Options

A few last questions

Simple answers before you begin

The complete method is made to be clear, practical, and easy to start.

Does this use “cry it out”?

No. The SleepBaby Method was specifically designed without the controversial “cry it out” approach.

What ages is it made for?

The method is designed to help families from the newborn stage through the toddler years.

How will I receive it?

It is a digital program delivered instantly, with unlimited access to the workshop and all three bonuses.

What if it is not right for us?

You have 60 days to explore the complete method. If it is not right for your family, contact us and we will make it right.

A calmer night can start with one clear plan

Ready to try The SleepBaby Method for yourself?

Get the complete digital method, all three bonuses, and instant access so you can begin tonight.

Ready when you areStart tonight
Click Here for Instant Access

The SleepBaby Method + Baby Sleep Music + Deep Into Dreams + Sleepy Siblings · 60-day guarantee

Ready when you are

Complete your order here

The complete method + all 3 bonuses. Instant access after confirmed payment.

The SleepBaby Method

Complete digital package. No subscription.

Total todayUSD · one payment$20
Need a different price?

Every accepted amount includes the same complete package and the same 60-day guarantee.

USD. The package and refund rights do not change with your price.

Secure payment options load here when you reach this section.

Payment details are handled securely by PayPal. PayPal Privacy Statement.

  • One payment
  • 60-day guarantee
  • Access after confirmed payment

Prefer a separate page? Open the dedicated checkout

What is included?
The complete SleepBaby digital package
  • The SleepBaby Method — the complete digital guide
  • Baby Sleep Music — the audio collection
  • Deep Into Dreams — the companion guide
  • Sleepy Siblings — practical help for two children

Every accepted price includes the same complete package.

How do I receive access?

Access opens after SleepBaby securely confirms your completed payment. Nothing is shipped. An approval window alone does not unlock access.

Your 60-day guarantee

If the package is not right for your family, email refund@sleepbaby.org within 60 days. Your chosen price does not change your refund rights. Read the refund policy.