How to sterilise baby bottles

Cleaning your baby’s bottles with soap and water is an important step, but it’s not the same as sterilising them. Sterilising baby bottles after cleaning them removes all bacteria and germs that might be present².

Your baby’s immune system isn’t as developed as yours, and is still developing as they grow. This means that they can be more susceptible to illnesses and infections. Sterilising baby bottles and other feeding equipment helps to kill bacteria and keep your baby healthy³.

Both breast milk and formula milk provide the perfect environment for bacteria to develop if bottles aren’t properly sterilised. Those bacteria may lead to your baby developing infections such as diarrhoea and vomiting².

You should sterilise all feeding equipment, including bottles, teats, and breast pumps, until your baby is at least 12 months old and their immune system has had time to develop¹.

There are several different ways you can sterilise your baby’s bottles and feeding equipment. We’ve created a handy guide to help you choose the right method for you⁴.

The most important thing is to find a way of sterilising baby bottles and other equipment that not only keeps your baby healthy as they feed, but also works around your lifestyle.

Follow these steps before you sterilise any of your baby’s feeding equipment¹:

1. Wash your hands thoroughly with soap and water.
2. Clean work surfaces you intend to use with hot, soapy water.
3. Check all bottles, teats and other equipment for damage.
4. Clean all equipment in hot, soapy water as soon as possible after use (use a clean bottle brush and teat brush to clean thoroughly).
5. Rinse all equipment in cold and clean running water.

If you prefer, you can clean your baby’s feeding equipment in the dishwasher by placing the bottles, lids and teats facing downwards (you might want to wash teats separately to make sure they’re entirely clean). You’ll still have to sterilise the equipment when it comes out of the dishwasher to kill any remaining bacteria⁵.

Germs and bacteria can’t survive in temperatures over 100°C, so submerging baby bottles and feeding equipment in boiling water can be an easy and effective way to sterilise them².

You will need:

• A saucepan with a lid
• Water
• Kitchen tongs that you only use for sanitising

1. Check that your feeding equipment’s care instructions to make sure everything is safe to be boiled 
2. Fill a saucepan with water and bring to the boil
3. Use kitchen tongs to place items in the water, making sure they’re fully submerged
4. Cover the saucepan and continue to boil for 10 minutes (you might want to set a timer for this)
5. Keep everything in the pan and remove just before use

Steam sterilisation works in a similar way to boiling, by allowing hot steam instead of water to kill off bacteria and germs. There are lots of different electric steam sterilisers for bottles available to buy, and most are easy to use.

Be sure to follow the manufacturer’s instructions to use your electric steamer correctly and safely.

As well as electric steam sterilisers, you can also buy steam sterilisers for bottles that go in the microwave. They work in the same way as electric sterilisers, by using steam to kill germs and bacteria.

Check the manufacturer’s instructions to learn how to sterilise feeding bottles in the microwave with your steam steriliser.

Don’t forget to check that your bottles, teats and other equipment are safe to microwave before using a microwave steam steriliser.

Cold water sterilisation uses chemical sterilisers mixed with cold water to kill germs and bacteria².

You will need:

• Sterilising chemicals (you can buy these in tablet or concentrated liquid form)
• A clean container with a watertight lid
• Floating cover or plunger (which should come with your steriliser)

1. Make the cold water sterilising solution in the watertight container according to the manufacturer’s instructions

2. Fully submerge all bottles and feeding equipment in the solution, making sure there are no air bubbles (you might need to use a floating cover or plunger to keep items submerged)

3. Leave the items for at least the length of time indicated in the manufacturer’s instructions

4. Change the solution every 24 hours

5. Remove equipment just before use and rinse using cooled boiled water from the kettle

After sterilising baby bottles and other equipment, it’s best to store them in the pan or steriliser until you need them. Most manufacturers recommend storing sterilised equipment for no longer than 24 hours. Any longer and it’s a good idea to re-sterilise before use¹.

If you do remove sterilised equipment before you use it, make sure to put the teats and lids on your bottles straight away. Always clean and dry your hands before touching anything that’s been sterilised, or use a pair of sterile tongs¹.

There are a number of ways you can sterilise your baby’s bottles, including boiling, electric and microwave steamers, and cold water sterilisation⁵.

As a general rule, you can store sterile bottles and other feeding equipment for up to 24 hours before you need to re-sterilise them. Always keep sterilised equipment covered in the pan or steamer until you’re ready to use it¹.

Yes, you can sterilise feeding bottles in the microwave using a microwave steam steriliser.

Yes, you should sterilise all equipment before each use to help protect your baby’s developing immune system⁵.

You should clean and sterilise your baby’s bottles before each use until your baby is at least 12 months old¹.

No. You can use a dishwasher to clean your baby bottles, but you’ll still need to sterilise them afterwards by boiling, steaming, or using a cold water steriliser⁵.

Yes, sterilising dummies every 24 hours can help protect your baby from infections. You can also wash your baby’s dummy with hot, soapy water between uses⁶.

Yes, you should sterilise all equipment involved in feeding your baby, including your breast pump⁴.