How to sterilise baby bottles (with and without a microwave)

Whether you’ve decided to breastfeed or bottle-feed with expressed milk or infant formula, it’s important to clean and sterilise all types of newborn feeding equipment to help keep your little one happy and healthy.

Newborn babies have vulnerable immune systems, meaning they’re far more susceptible to everyday germs and bacteria that are usually harmless to adults. These can cause illness in young children – vomiting, diarrhoea, and oral thrush are particularly common.

Sterilising baby bottles and other feeding equipment reduces the likelihood of your baby coming into contact with these germs and therefore, lowers their risk of illness. This guide looks to answer any questions you may have regarding the sterilisation process, from how to sterilise baby bottles and just how long do bottles stay sterile for, to knowing how to store sterilised baby bottles safely!

Key Steps:

1. Sterilising baby bottles after every use to protect your baby’s vulnerable immune system.

2. Wash any equipment thoroughly before you begin the sterilisation process.

3. Knowing how to sterilise baby bottles using a method suitable for your lifestyle can help make sterilisation hassle-free.

Sterilising baby bottles: What equipment is available?

Worrying about how to sterilise baby bottles is common in all new parents but it’s actually very simple. You can choose to purchase a dedicated baby bottle steriliser or use objects and items that you already have in your home for the same purpose. Just remember that before using any form of baby bottle steriliser you need to thoroughly clean the equipment using warm, soapy water – your regular dishwashing soap will be fine for this, but it’s also worth buying a soft-bristled bottle brush that will prevent damage to teats and pump tubes.

Below, you'll find five options for sterilising baby bottles and other feeding equipment.

How to sterilise baby bottles with an electric steamer

1. Fill the steamer with a small amount of cold water.

   Read your product’s instructions for the exact amount, but as a general rule, steamers that hold 6 bottles or the equivalent typically need around 200ml.

2. Place the clean feeding equipment into the baby bottle steriliser.

   Remember that the water and heating element are at the bottom of the device, and steam rises. This means that items should be placed with their openings facing the bottom: teats should be the right way up, and bottles should be placed upside down.

3. Replace the lid of the steriliser.

   Ensure you have a tight seal all the way around – if there is even the smallest gap, the steam will simply escape.

4. Turn the steamer on and leave for the instructed time.

   This is usually anywhere from 5 to 10 minutes. Do not attempt to remove bottles immediately, as they will be very hot.

5. If the lid has not been removed, bottles can be left in the steamer for up to 6 hours.

   Once the lid has been opened, however, bottles need to be assembled rapidly, with the lids on, to prevent the insides from becoming contaminated.

How to sterilise baby bottles in microwaves

1. Make sure your microwave is clean.

   Clean a microwave to help ensure it’s germ-free.

2. Fill the bottles halfway with water.

   Then, put them in the microwave.

3. Take care with accessories.

   Place any rubber nipples and other accessories in a glass bowl filled with water deep enough to cover them.

4. Microwave!

   Microwave the items on the ‘high’ setting for a minute and a half.

5. Allow to cool.

   Allow to cool before removing them from the microwave. Always wash and dry your hands before touching sterilised items.

How to sterilise baby bottles by boiling them

1. Fill a large pan with cold water and place the feeding equipment in.

   Ensure that all items are completely covered by the water and they are no air traps.

2. Use a heavy plate or bowl to place on top of the pan, almost in contact with the water.

   This will keep all items below the surface of the water.

3. Bring the pan of water to a rolling boil.

   Continue to do so for 10 minutes.

4. If you leave the lid on, bottles can stay in the pan for up to 6 hours.

   Although, it’s better to assemble them once they’ve cooled enough. Assembled bottles can typically be left for 24 hours before needing to be re-sterilised.

How to sterilise baby bottles in the dishwasher 

If you have a dishwasher, this can be used as both a cleaner and a baby steriliser. It’s important, however, that you ensure that the feeding equipment you have is suitable for dishwashing (use the top shelf if necessary), and you will also need to use a very hot program of over 80 degrees.

Many new parents find the dishwashing method to be too much hassle, as it tends to damage bottles and equipment quicker than some other methods, and there is a chance of teats flipping over with the pressure of the water, which means they accumulate dirty water and need to be washed and sterilised again. Take a look at our guide to what you can and can’t put in the dishwasher for more general dishwasher information.

How to sterilise baby bottles with cold sterilisation 

Cold sterilisation is perfect for parents who frequently need to use a baby bottle steriliser on the move, or while out and about without access to electricity or boiling water.

1. Using a clean plastic tub or bucket, a sterilising solution or tablet (available from supermarkets) can be added to water, and the baby items placed in.

2. Ensure all items stay under the water for at least 30 minutes – preferably longer.

3. The water and solution can be reused as needed but should be changed after 24 hours.

How do I choose a baby bottle steriliser? 

Choosing a method for sterilising baby bottles will really depend on your individual circumstances and preferences. Parents that have the time and are looking for inexpensive options might go with boiling on the hob, while those with little time to spare may prefer a quick electric or microwave steamer. Cold sterilisation is equally as good, but many prefer to keep their sterilising methods natural and prefer to avoid sterilising tablets and solutions.

How long do bottles stay sterile for?

How long a bottle stays sterilised for largely depends on how you store them. You can find some storage ideas below.

If you have used an electric steamer to sterilise your bottles, items can remain sterile for up to 24 hours with the lid closed, depending on the model you have used.

How to store sterilise baby bottles

Now that you’ve chosen a sterilisation method that works for you, it’s important to know how to store sterilised bottles to keep them clean. If you’re using an electric steamer, it’s generally best to leave the bottles and accessories in the steamer until you need to use them.

If you have used an alternative method, it’s important to store sterilised bottles on a clean, disinfected surface, or on the upturned lid of the steriliser. Make sure you have an effective disinfectant and disinfectant wipes to hand to help keep your surfaces and cupboards clean.

How long should I keep sterilising baby bottles for? 

You’ll be glad to hear that once your baby reaches 12 months of age, their immune system is usually strong enough to fight off most everyday germs and bacteria, so you can stop sterilising baby equipment at around the one-year mark. It’s still a good idea to continue to wash bottles and other equipment thoroughly and do so immediately after use.

While having a baby can be overwhelming, hopefully, this simple and easy guide has helped to make at least one part of looking after your child hassle-free! If you’re a first-time parent or want a refresher on what to do when preparing for a baby, check out this complete guide for preparing for a baby.