What is a steriliser?

A steriliser kills all the bacteria found on bottles, teats, breast pumps or anything else that comes into contact with milk and your baby’s mouth. This is done is done by steam or with a chemical solution.


Warm milk is the ideal breeding ground for germs and harmful bacteria. Your baby doesn’t have a fully developed immune system yet and without the necessary antibodies to stave off bacteria and parasites, your baby is susceptible to illnesses such as gastroenteritis.

What type do you need?

There are three main types of steriliser you can choose from:

  • Microwave steam - if you opt for a microwave steriliser then check your microwave is working properly at the stated wattage and is large enough to fit one - some of them are pretty big. Also check that you have room to store your microwave steriliser, as you’ll presumably need your microwave for other things too!
  • Electric steam - if you have plenty of workspace then a stand-alone electric steam steriliser maybe your best option as it only gets used for baby stuff and won’t be in the way of doing other household jobs.
  • Cold water - this can be handy for travel, as you’re not reliant on there being a microwave or a handy power socket at your destination. While just as safe and effective, the advantage of steam over cold water sterilisation is there’s no smell and steam sterilising can be faster.

Do you want a fast-to-clean option?

Cold water and microwave steam sterilisers just need washing on a regular basis. An electric steam steriliser needs de-scaling to ensure the element (that’s the bit that heats up the water to make steam) is free of mineral deposits (lime scale) and can reach a high enough temperature. You de-scale your electric model by using citric acid or white vinegar and running a steam cycle.

If you want an option for travelling (and have access to a microwave) then microwave steriliser bags provide a perfect solution

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How will you use it?

If you’re breastfeeding, not expressing and only give the occasional bottle when you’re out, a travel steriliser that fits one or two bottles and goes in the microwave will be easy to use and store.

If you’re bottlefeeding you may need up to sterilise up to eight bottles in a day, so a bigger unit will be more efficient.

If you’re expressing breast milk as well, you’ll need a steriliser that has space for a breast pump.

With all types of steriliser you’ll need somewhere to store it. A microwave steriliser can only be hidden in the microwave when you’re not using it to heat other things, and an electric unit will have to take up worktop space.

What style of bottles does your steriliser need to fit?

Do you use wide neck bottles (short and fat), standard bottles (tall and thin), or anti-colic bottles (may have many parts for its venting system)? This will influence your choice of steriliser. Companies tend to make their sterilisers to fit their own bottles - for example, the Born Free Microwave Steriliser can’t take standard bottles easily, but has an inner tray with markings showing how to fit all your Born Free bottle parts. Other brands may hold a different number of bottles depending on style – the Lindam Rapid steam steriliser handles six wide neck or nine standard bottles.

Most sterilisers will tell you on the box how many and what type of bottles fit, so check to see if it’ll be enough for your needs.

What do you need to know about sterilising?

Government guidelines are that you should sterilise all milk feeding equipment for one year and all weaning equipment until 6 months (if you start weaning early).

Before sterilising, all feeding equipment must be washed with hot soapy water and rinsed thoroughly and your hands and work surface need to be clean.

Both electric and microwave steam sterilising involve adding the correct amount of water to a sterilising unit – follow the instructions!

Bottles should be used immediately but will often remain sterile until the lid is removed for up to eight hours, those this time frame varies from model to model. For cold water sterilisation, the sterilising solution can be used for up to 24 hours.

Once you’ve removed your baby’s bottle and teat from a steriliser you should use them as soon as possible or store ready-assembled in the back of your fridge (where it’s coldest). This will avoid the possibility of contamination. Once bottles and teats show signs of wear and tear, replace them immediately as cracks within the plastic may become difficult to sterilise.

In other countries advice varies. In Canada they only recommend sterilising for the first few weeks, in the US for the first three months and in some countries a dishwasher is seen as adequate sterilisation. In order to sterilise properly a dishwasher needs to be regularly cleaned, not used for any other purpose at the time and must reach temperatures of 80 degrees C.


Where do you start?

Before you buy anything, check out our in-depth reviews of sterilisers.