Sterilising your baby's equipment including bottles

Your baby is most vulnerable to diseases and illnesses during the first year of his life. If bottles are not sterilised then you risk having bacteria build up and potentially causing your baby to become ill. Fortunately sterilizing your baby’s bottles and nipples is dead simple. Read on to find out about all the different ways to keep your baby feeding equipment sanitized.

Before you sterilise, you’ll need to clean the used bottles thoroughly. Wash the bottles in clean soapy water, along with the teats, retaining rings, caps, and the manufacturer’s scoop that comes with the tin of formula. This way, every trace of milk is removed.

It's best to clean the equipment as soon as possible after a feed, before the milk has had a chance to dry on. Use clean, hot, soapy water and a clean bottle brush (NHS 2012a). Take extra care when washing the teats to make sure any stubborn milk curds come off, as these can survive the sterilising process.

To clean the teats fully, wash the inside of the teat by turning it inside-out. When you’ve washed everything, carefully rinse off all the detergent.

You can also use a dishwasher to wash your baby’s bottles, as long as the bottles are dishwasher safe. You may want to wash the teats separately, though, to be sure they're totally clean.

Check teats and bottles carefully and throw out any that are badly scratched, split, or cracked. Bacteria can stay in damaged surfaces and survive the cleaning and sterilising process (NHS 2012a).

How do I sterilise my baby's equipment?

There are several ways to sterilise your babies feeding equipment. Electric steam sterilising and microwave sterilising are the most popular. However, for times when you don’t have access to electricity, use traditional methods, such as cold-water sterilising.

Electric steam sterilising

Electric steam sterilising

Electric steam sterilisers are quick and efficient, taking eight minutes to 12 minutes, plus cooling time. They can keep bottles sterilised for up to six hours if you leave them in the steriliser with the lid closed. Many steam sterilisers can hold up to six bottles at a time, and have a rack for smaller items such as teats and dummies.

Make sure bottles, teats, and other equipment are placed with their openings face down. Then you can be sure that they are fully sterilised. Check that you only put in equipment that is safe to steam. Some parts of breast pumps may not be suitable.



Many baby bottles can be sterilised in the microwave on their own. This is a quick and easy way to sterilise individual bottles - it takes just 90 seconds. If you use this method, remember to leave the bottles unsealed so that pressure cannot build up inside the bottle.

You can also buy steamers for microwaves, but you won't be able to put anything metal inside them. These steamers take about three minutes to eight minutes to work plus cooling time, depending on the model and your microwave wattage.

These sterilisers' main advantage is that there is no smell or taste left afterwards. The items also remain sterile for three hours if you keep the steriliser lid closed (FSA/NHS 2012). Take care when removing the lid of microwave steam sterilisers, as the inside can become very hot.

Cold-water sterilising

Cold-water sterilising

To sterilise your baby’s bottle-feeding equipment with cold water, use a sterilising solution dissolved in cold water. Some solutions also come in tablet form. The solution kills bacteria very effectively. You’ll need to change the solution every 24 hours.

You can buy special sterilising units for cold-water sterilising. Or you can use a clean bucket or plastic container with a lid. However, if you are not using a special unit, try not to reuse the same plastic container for sterilising. It is also not a good idea to use an ice cream tub. Sometimes the sterilising solution can affect the plastic and contaminate the solution.

If you use a bucket or container, use something weighty, such as a heavy plate, to keep the bottles and other equipment completely under the solution. You need to check that there are no air bubbles left in the bottles, and keep everything submerged for at least 30 minutes to sterilise it all (FSA/NHS 2012).

Also, always follow the manufacturer's instructions as to how much water and sterilising solution to use. If your solution is too concentrated or too dilute, it could affect how well your baby's feeding equipment is sterilised.

Take out bottles and teats only when you need to use them. Give each item a shake as you take it out, and rinse off the fluid with cool, boiled water (Crawley and Westland 2013).

How long should I continue sterilising?

Continue to sterilise your baby’s bottle feeding equipment for at least his first year (NHSinform 2011). You may think sterilising is rather pointless when your baby is putting all sorts of things in his mouth. However, your baby's immune system is still developing and it's easy for him to pick up infections during his first year. The bugs that stick to milk curds in partially cleaned bottles can be particularly nasty.

By the time your baby is one year old he'll have started to produce his own antibodies and be more resistant to harmful germs. However, it's a good idea to carry on sterilising bottles, Dummies, and teats until your baby stops using them.