Skip to content

How to Address and Prevent Bad Smells in Baby Bottles

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, 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, 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.