How to sterilize baby bottles

How to sterilize baby bottles and pacifiers

Looking for advice on how to clean and sterilize baby bottles and pacifiers as well as other baby equipment?

Keeping baby bottles, pacifiers and other items that your baby comes into contact with clean and germ free is important to prevent your baby getting the stomach flu and other nasties. Some experts also recommend sterilizing these items if:

  • your baby is younger than 3 months;
  • your baby is considered high risk due to being premature;
  • your baby has been ill;
  • you don’t have access to clean drinking water.

Even if your baby does not fit into any of the above criteria, you might want to sterilize items every so often to lower the risk of your baby getting sick.

Methods that can be used to sterilize baby bottles and pacifiers include:

  • using an electric sterilizer;
  • using a UV sterilizer;
  • using a microwave sterilizer;
  • using boiling water;
  • putting items in the dishwasher; and
  • using a sterilization tablet in cold water.

Quick guide: which sterilization method is right for you?

You want the cheapest methodDishwasher or boiling water method
You want to be 100% sure the bottles etc. are sterileUV sterilzer or electric sterilzer
You want to sterilize more than just bottles and pacifiers (such as toys)UV sterilizer
You want the most convenient methodUV sterilzer, electric sterilizer or microwave steamer sterilizer
You want to be able to sterilize while travellingPortable UV sterilzer or steriliation tablet
You want the quickest methodMicrowave steamer sterilizer or electric sterilizer
You have limited bench spaceAvoid using an electric sterilizer or a UV sterilizer

How to sterilize in an electric sterilizer

After thoroughly scrubbing any milk reside from the bottles and nipples, place the bottles and nipples in the sterilizer with some water. Pacifiers and pump parts can also be sterilized by putting them on the top shelf of the unit. Once the sterilizer is switched on, the water will turn to steam and anything inside will be sterilized. The sterilizer automatically turns off once the cycle is complete – in about 5 minutes.

The bottles will remain sterile in the unit for 24 hours once they have been sterilized.

This video will give you an idea of how an electric sterilizer works:

Pros of electric sterilizers:

This method is a great solution if you are going through a lot of bottles a day as most units hold 6 bottles at a time. For newborn babies who are eating every 3 hours for example, that gives you 18 hours of coverage. You can simply wash and sterilize all your bottles at the end of the day.
It is a very effective method of sterilization. Once you turn it on, it is set and forget.
It is pretty quick – a cycle takes about 5 minutes to complete.
The unit is guaranteed to reach the optimum temperature to sterilize the bottles and pacifiers.
 The unit is light and can easily be transported if you are going on holidays etc. and need to take it with you. Be aware that you will need an electricity outlet.
No chemicals are involved.

After the bottles are sterilized, you can store them inside the sterilizer for up to 24 until you are ready to use them.

Cons of electric sterilizers:

X They are more expensive than most of the other options, although you can buy relatively cheap, smaller, portable models for travel or if you have an infrequent need to sterilize.

X Electric sterilizers need to be descaled every 4 weeks or more often if you notice limescale building up – see FAQS below for instructions on how to descale the sterilizer.

X If you are using an electric sterilizer frequently, you are going to want to keep it out on your bench. However these sterilizers take up a bit of space. If bench space is an issue, you might want to consider one of the other methods of sterilization.

How to sterilize in a UV sterilizer

A UV sterilizer uses ultraviolet light to get rid of bacteria and viruses. The UV sterilizer is safe to use on not only bottles and pacifiers but also on other smallish items such as pump parts, TV remotes, keys, toys etc.

After cleaning the bottles to get rid of any milk residue, you simply place the items inside the UV sterilizer unit and switch it on. The unit will take care of the rest.

This video will give you an idea of how a UV bottle sterilizer works:

Pros of UV sterilizers:

 UV sterilizers can sterilize multiple bottles at once so are a good option if you are using a lot of bottles a day.

 UV sterilizers are probably the easiest of all the methods to use as there is no water involved.

 They are designed to be set and forget and once the cycle is completed, you can feel assured the bottles have been effectively sterilized.

 Unlike electric sterilizers that use steam, there is no need to descale a UV sterilizer as there is no limescale build up.

 You can sterilize other items in the UV sterilizer such as remote controls, keys, jewellery, toys, toothbrushes etc because nothing gets wet in the UV sterilizer.

 Most UV sterilizers have a setting that will keep the bottles sterilize until you are ready to use them.

No chemicals are used.

Cons of UV sterilizers:

X They are the most expensive of all the options.

X The filter in the UV sterilizer needs to be changed periodically – about once a year. The UV lamp bulb may also need to be replaced.

X A UV sterilizer takes a little longer to sterilize than an electric sterilizer (minimum 10 minutes up to 50 minutes).

X The UV sterilizer takes up bench space. However they eliminate the need for a drying rack as they can be used to both dry the bottles and store them to keep them sterile during the day.

How to sterilize using a microwave sterilizer

Using the microwave to sterilize bottles and other accessories is a quick and pretty mess free method if a microwave sterilizer is used. Bottles will be sterilized in 2 -6 minutes depending on microwave wattage. Note that time needs to be added to this for the bottles etc to cool down.

After cleaning the bottles and accessories, add the recommended amount of water into the base of the unit and place the items in the sterilizer. Put the sterilizer in the microwave for the required amount of time. The water will turn to steam and anything inside the unit will be sterilized.

This video will give you an idea of how a microwave sterilizer works:



Pros of microwave sterilizers

No chemicals are used.

It is a good option if bench space is an issue as it is compact and can easily put away when not in use.

Safe to use on breast pump parts.

Lightweight so can be used for travel.

Cheaper than electric sterilizers or UV sterilizers.

Cons of microwave sterilizers

X  Doesn’t hold as many bottles as the electric sterilizer or the UV sterilizer.

X  Possible to get steam burns if instructions aren’t followed carefully.

X  The water remaining in the sterilzer after a cycle is complete will be very hot. Burns are possible if the unit is removed from the microwave before the water has had a chance to cool down.

X  It is recommended that distilled water be used in the unit to prevent limescale built up.

X  The unit needs to be wiped down after each use to prevent limescale buildup.

How to sterilize baby bottles and pacifiers in boiling water

Using boiling water is an old school method of sterilization. Take all the parts of the bottle apart and thoroughly scrub the bottles and nipples to remove any milk residue as per the other methods of sterilization. Then put the bottles, nipples and pacifiers in a large pot of water (making sure everything is submerged in the water) and bring the water to a boil.

Keep the water boiling for 10 minutes (always check the bottle manufacturer’s guidelines to see if the bottle can withstand boiling). Remove the items with clean tongs and let the bottles dry so they don’t go mouldy. Don’t use a dish towel that has been used to dry the dishes etc. as it could harbor  bacteria. Instead use paper towel and let the bottles drip dry. If not using immediately, store the bottles etc. in a clean container.

Make sure bottles, nipples, pacifiers etc. are thoroughly cooled before giving them to your baby.

Pros of the boiling water method:

It’s cheap – you probably have all the necessary equipment already.

No chemicals are used.

This method doesn’t take up bench space but you will need a space to dry the bottles.

Cons of the boiling water method:

X  If you are sleep deprived/ busy it is very easy to forget about the bottles and let the water boil away. Setting a timer may help with this.

X  Not all bottles can be sterilized using this method. Glass bottles may crack and some brands of plastic bottles may melt – check the manufacturer’s guidelines before using this method of sterilization. Bottles containing BPA should definitely not be sterilized using this method as the heat may cause the BPA to leach from the plastic. The dangers of using bottles that aren’t BPA free have been well documented.

X  Pacifiers and nipples may be worn out more quickly by this method.

X Pump parts may not be able to withstand this method of sterilization.

How to sterilize baby bottles and pacifiers in the dishwasher

Running bottles etc through the dishwasher is a convenient method of cleaning them but did you know that not all dishwashers are capable of sterilizing your baby’s equipment as they don’t get hot enough.  If your dishwasher does not have a sanitize setting and an NSF/ANSI Standard 184 Certification, another method of sanitization should be used.


Thoroughly wash the bottles to remove milk residue and then place them on the top rack of the dishwasher. Smaller items should be placed in a basket. Then use the sanitize setting on your dishwasher. If items aren’t completely dry at the end of the dishwashing cycle, air dry them on a clean dish towel or on paper towel.

Pros of using the dishwasher to sterilize baby bottles:

Convenient, no fuss method.

Cons of using the dishwasher to sterilize baby bottles:

X  Not all dishwashers are effective at sanitization.

X  Takes longer than some of the other methods.

X  Not all bottles are dishwasher safe. Bottles containing BPA should definitely not be put in the dishwasher as the heat may cause the BPA to leach from the plastic.

How to sterilize bottles when travelling

Using a sterilization tablet (also called the “cold water sterilization method”) is a great option if you need to sterilize bottles and accessories when travelling or camping and don’t have access to any equipment, or electricity. The basic idea is that you add the tablet to a tub of water and let the tablet dissolve. Then add the bottles, ensuring that they are fully submerged in the water (you might need a floating cover for this).  The sterilization process takes about 30 minutes.

You could also use a UV portable sterilizer for travel.

Pros of the cold water method

Excellent option if you are travelling.

Possible option if you are worried about boiling/ heating plastic and silicone repeatedly.

Can be used to sterilize other items such as toys or clothing.

Cons of the cold water method

X Has a chlorine smell.

Frequently asked questions

How do I clean my baby’s bottles?

Cleaning and sterilizing are 2 different things. Sterilization is the process of killing germs. Cleaning involves removing all visible signs of milk etc. To clean a baby bottle, wash it with warm soapy water and use a clean bottle brush to thoroughly remove all traces of milk. Rinse again with water to get rid of the soap.


Do I really need to sterilize my baby’s bottles and pacifiers etc?

The advice is conflicting as to whether sterilization is required. Health experts in the UK and Australia for example, recommend sterilizing the baby’s feeding equipment for  at least 12 months.  The advice in the US is that sterilization is not required unless:

  • your baby is younger than 3 months; or
  • your baby is considered high risk due to being premature; or
  • your baby has been ill; or
  • you don’t have access to clean drinking water.

How often do I need to sterilize my baby’s bottles?

If you are following the UK health guidelines or the Australian  guidelines, they should be washed after every use.

The US guidelines  state that they don’t need to be sterilized but do need to be thoroughly washed after each use. You may still want to sterilize bottles, pacifiers and pump parts every so often to be 100% sure they are germ free.


Can I use the freezer to sterilize bottles?


No. A freezer doesn’t kill germs. It just prevents them from multiplying. When you take the bottles out of the freezer they have the same germs as they did when they went into it.


Do I need to dry the bottles after sterilization?                                 

No, any water left inside the bottle is sterile. If you are not using the bottle straight away, it is important to ensure they dry so they don’t go mouldy. The best method to do this is to let them drip dry on a paper towel. Drying them with a tea towel may introduce harmful bacteria.


How do I descale an electric sterilizer?

Electric sterilizers need to be descaled every 4 weeks or more often if you notice limescale building up.  You can either use a descaling product or you can simply use white vinegar. Using the white vinegar method:

  1. Remove the top bottle rack. Wipe the inside of the sterilizer with a sponge or damp cloth, paying particular attention to any limescale build up.
  2. Pour in 1 cup (250 ml of white vinegar) and leave for between 30 mins and 24 hours depending on how bad the limescale is
  3. Then pour the vinegar out and rinse with cold water. Wipe away any remaining bits of limescale.
  4. Run the sterilizer as normal without any bottles etc. for one cycle.



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