How to sterilise bottles and baby feeding equipment safely

How to sterilise bottles

What are the rules for bottle sterilising?

Do you really need to sterilise baby bottles?

The short answer is yes.

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The long answer…

Yes. For the first whole year of your baby’s life. And yes it seems like a long time.

The reason is because your baby’s immune system is less resistant to nasty bugs than yours. Therefore you must sterilise all milk feeding equipment.

This applies whether you are bottle feeding powdered infant formula milk, ready-to-feed liquid formula or expressed breast milk.

Sterilisation kills germs and helps prevent stomach upsets, diarrhoea and serious infection.

How to clean baby bottles properly

The sterilising process begins with a proper clean. 

Before sterilising, scrub bottles, teats, breast pump parts and other feeding equipment in hot soapy water.

Use a specially designed bottle brush to reach all bottle and teat surfaces properly. You need to be meticulous about this. 

It is vital to get rid of traces of old milk from the insides of bottles, which are a breeding ground for bacteria.

Then rinse well with cold water.        

You can also put feeding equipment in the dishwasher, but it won’t come out sterilised. You must sterilise afterwards.

How to sterilise bottles in five different ways

You have a few different methods of sterilisation to choose from. Pick the one that suits you best, or mix and match.

1. Electric steriliser

An electric steam steriliser sits on your worktop and uses natural steam sterilisation to sterilise bottles and other feeding equipment.

Steam sterilisation involves no chemicals and is a highly effective method of killing bacteria.

An electric steriliser is easy to use – simply add water and switch it on. Maintenance includes descaling to remove lime scale build-up, especially in hard water areas.

An electric steriliser takes around five minutes to complete the sterilisation cycle.

Bottles will typically stay sterile inside the steriliser for up to 24 hours (refer to the manufacturer’s guidelines). If a bottle isn’t used within this time, you will need to re-sterilise. 

2. Microwave steriliser

A microwave steriliser also works by turning water to steam.

After adding water, it takes around 5 minutes to sterilise bottles. Contents remain sterile for up to 24 hours with the lid unopened (again check manufacturer’s guidelines). 

When you take the lid off, you can use it as a clean surface for preparing feeds.

There is no descaling involved – keep the unit clean by washing it in the sink or dishwasher.

With its dish-shaped design, a microwave steriliser sits conveniently inside your microwave when not in use. It doesn’t need to take up space on your worktop.

Light and portable with no power cable to worry about, you may find it more suitable for travelling than an electric steriliser.

If you buy a microwave steriliser, make sure your microwave is big enough to accommodate it before you buy!

If you have no microwave available, fill the unit with cold water sterilising solution and put your bottles in that.

Electric and microwave steam sterilisers are usually designed to fit a particular brand of baby bottle. They may not fit all types of bottles.

3. Milton cold water steriliser

A cold water steriliser may appear old fashioned in the light of modern technology. But it is just as effective as steam sterilisation and certainly has its advantages.

You simply fill a bucket with water and Milton (or other sterilising solution), add your bottles, and wait for 15 minutes.

Plastic toys, dummies, teething rings and other accessories can also be sterilised in this way.

(You can buy a specially designed bucket with a lid that ensures equipment stays fully submerged.)

The solution stays sterile for 24 hours, during which time you can add and remove things as and when you need to.

This is a bonus because you can just get out a single item and the other things inside will remain sterile.

Just be aware of when you need to change the solution. There is no need to rinse items when you take them out.

Cold water sterilising has the added advantage of being easier for travel because it requires no power source or microwave. You can use it anywhere.

An electric or microwave steriliser will be of no use to you in the event of a power cut. So it won’t hurt to keep some Milton tablets in the cupboard just in case!

4. Boiling baby bottles

How do you sterilise baby bottles without a steriliser? Is boiling water enough to sterilise baby bottles?

Yes. You can sterilise bottles, teats and other feeding equipment by boiling them in a large pan of water.

Firstly make sure items are safe to boil. Then submerge them in the water completely below the surface and boil them for at least 10 minutes, with the lid on.

It is best to keep the lid on and remove bottles just before you need them.

Regularly check teats for damage if you boil them. They will deteriorate faster and need replacing more often with this method of sterilisation.

5. UV sterilisers

A UV steriliser uses a UV lamp to sterilise bottles and feeding accessories, instead of steam or chemicals.

It uses invisible ultraviolet light to disinfect against bacteria, mould and viruses. It is the same technology used to sterilise medical equipment in hospitals and other healthcare settings.

The Tommee Tippee ultra UV 3-in-1 steriliser sterilises and dries, so you have no more wet bottles. You can sterilise and dry multiple bottles in 60 minutes, or simply dry already sterilised bottles in 30 minutes.

The sterilised equipment remains sterile inside the unopened unit for 24 hours.

Assembling sterilised bottles

Before you touch sterilised equipment make sure your hands are clean. The same goes for surfaces you are using to assemble bottles.

When putting together sterilised bottle parts do not dry them first. The water clinging to teats and the insides of the bottles is sterile, and wiping it off may transfer germs.

Try not to touch sterilised teats with your fingers. Use sterilised teat tongs to assemble the teats.

How long do bottles stay sterile once removed from steriliser?

The World Health Organisation states it is best to leave sterilised bottles and feeding equipment in the steriliser until just before you need it.

If you remove equipment from the steriliser and do not use it straight away, store it in a clean place.

You should fully assemble bottles and teats. This protects the inside of the sterilised bottle and the teat surfaces from contamination.

But how long does an empty bottle stay sterilised before you must sterilise it again?

According to Tommee Tippee, you can store clean, sterilised assembled bottles safely for up to 24 hours. 

You can also make up bottles of formula in advance before they are needed, instead of leaving them empty. (Although convenient, this practice is generally frowned upon by health professionals.)

How do you sterilise baby bottles when travelling? 

Whether you are travelling by car, plane, train, staying in a hotel, tent, or even backpacking, you may not have access to your usual sterilising kit.

Here are four easy solutions to your sterilising needs whatever situation you find yourself in.

1. Microwave sterilising bags

Steam sterilising bags are for use in the microwave. These work the same way as a regular microwave steriliser, they just don’t hold as much stuff.

Steriliser bags are lightweight, portable and take up little space.

The Munchkin steriliser bags are for sterilising bottles, teats and accessories. With 30 uses for each bag, they are perfect for sterilising bottles on holiday.

These are also useful if you don’t routinely sterilise lots of bottles at once, and only sterilise feeding equipment occasionally.

2. Travel steriliser

A travel steriliser such as the Milton solo travel steriliser, is a quick and easy way to sterilise one single bottle.

Use it for microwave steam sterilising or cold water sterilisation with a Milton tablet.

3. Self sterilising bottles

Self-sterilising bottles don’t need separate sterilising equipment.

The MAM self-sterilising bottles are ideal for when you are out and about. Simply fill a bottle with 20ml of water, assemble it according to instructions, and heat for 3 minutes in the microwave.

After sterilising, if you leave the assembled bottle untouched, it will remain sterile for up to 48 hours.

You need to be extra careful about keeping your microwave clean using this method. The outside of the bottles are not protected by an outer sterilising unit.

4. Portable UV steriliser

This works the same way as a regular UV steriliser, using ultraviolet light. You can take it with you when you are out and about and sterilise bottles quickly on the go.

The Nuby portable UV steriliser does not require a plug socket, you charge it up before you go.

It consists of a lightweight compact bag that you can carry over your shoulder or fasten onto the pram. Pop a bottle in when you need one, wait for 3 minutes, and it’s done.

When to stop sterilising bottles 

You must continue to sterilise bottle feeding equipment until your baby is one year old. Then you can stop.

The same with dummies and teething toys.

By this time your baby’s immune system is mature enough to cope with potentially harmful germs.

If you are weaning your baby early, his bowls and spoons used for solids should also be sterilised until he is six months old.

Bottle feeding sets with steriliser

If you know you are going to bottle feed, consider investing in a bottle feeding set with a steriliser before you give birth. Then you can have sterilised bottles at the ready as soon as your baby needs them.

A complete feeding set is also useful if you suddenly change your mind about breastfeeding vs bottle feeding. It is easy to purchase everything you need at once without too much thought and panic. 

The Tommee Tippee complete feeding set has everything you need to get started bottle feeding. Including:

  • electric steam steriliser
  • bottles and teats
  • tongs
  • bottle brush
  • milk powder dispensers,
  • insulated bottle bags
  • bottle warmer

It can feel like an overwhelming task sterilising bottles every day. But you will soon get used to it, and it will become a normal part of your routine.

So do your research, and you will soon find ways to make your life easier.

More information you may find useful:

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How to sterilise baby bottles and feeding equipment