Key Summary
Proper cleaning and sterilising of baby bottles is crucial to protect babies from infections due to their immature gut and immune system.
There are several methods you can use to sterilise baby bottles, including boiling, steam, UV, and chemical sterilising.
It’s best to keep sterilising bottles until babies are 12 months old
How to sterilise and clean baby bottles
If you’ve recently been blessed with a little bundle of joy, chances are your formerly Instagram-worthy kitchen bench has been taken over by baby bottles, cleaning and sterilising equipment. With as many as 12 feeds in any 24-hour period for a typical newborn, learning how to properly clean and sterilise baby bottles helps keep your baby safe. “It’s important to protect little babies from infections because their gut and immune system is immature,” says paediatric dietitian Kat O’Brien. “Milk is very nutrient-rich, which is why it’s good for babies, but it’s also a really good environment for bacteria to grow.”
Follow Kat’s simple guide.
Why do I have to sterilise baby bottles?
Sanitising baby bottles is a non-negotiable, since bacteria can thrive in any milk and saliva that’s been left in the bottle. “Babies can get dehydrated very quickly, which means diarrhoea and vomiting can be very dangerous for them,” says Kat. “They're at a much higher risk of being acutely unwell.”
Although the water supply in Australia is generally safe, you also need to sterilise water before giving it to babies. Even bottled water, according to Kat. “Formula isn't sterile either, so you need to boil the water, then cool it so it’s still hot enough to help to kill some of the bacteria in the formula. You then want to mix it, then let it sit until it’s a drinkable temperature for your baby.”
Always check the temperature of prepared baby formula before giving it to bub by dripping a few drops onto the inside of your wrist. It should feel just a little warm.
How to sterilise baby bottles
Once you’ve cleaned your baby bottles (see below for how to wash them), you need to sterilise them to kill those nasty bugs. There are four key ways to sanitise baby bottles, so choose one that works best for you and your family. If you don’t use a baby bottle within 24 hours of sterilising it, you need to sterilise it again (sorry!). Always follow the bottle manufacturer’s instructions as some sterilising methods may suit certain bottles more than others
1. The boiling method
How to do it: Separate the clean bottle parts and place them in a large pot with enough water to cover them. Bring the water to the boil and boil for five minutes with the lid on. Let the water and bottles cool in the pot before removing and allowing them to air dry.
What equipment you’ll need: A kitchen pot or large saucepan.
Who it’s good for: Anyone, especially those with a limited budget.
Need-to-know info: Keep kids away from the stove and boiled water. Over time, this method may warp parts of your bottle
2. The chemical method
How to do it: Add two Milton antibacterial tablets or one capful (30ml) of Milton antibacterial solution to four litres of cold water. Add your clean separate bottle parts to the solution and wait 15 minutes for them to be sterilised.
What equipment you’ll need: A clean bucket or a Milton sterilising unit.
Who it’s good for: Parents who are pressed for time.
Need-to-know info: You can leave bottles in Milton solution for up to 24 hours.
3. The steaming method
How to do it: Place the clean separate bottle parts into a steam steriliser, making sure there’s room for steam to circulate around each bottle, teat and screw cap. Add water and turn it on, or transfer the steamer to a microwave, depending on the manufacturer’s instructions.
What equipment you’ll need: A steam steriliser.
Who it’s good for: Parents who want minimal cleanup, plus those with multiple babies.
Need-to-know info: Some steam sterilisers will also dry your bottles.
4. The UV method
How to do it: Place the clean separate bottle parts into a UV (ultra-violet) steriliser and dryer, which uses UV light to kill harmful bacteria and viruses. Switch on as per the manufacturer’s instructions.
What equipment you’ll need: A UV bottle steriliser.
Who it’s good for: Eco-friendly families who want a water-free, energy-efficient option.
Need-to-know info: Some models will emit UV light regularly while in storage mode to keep contents sterile.
When can you stop sterilising baby bottles?
Even though your baby will start crawling around, often putting dirt in their mouth in their first year, it’s best to keep sterilising bottles until they’re 12 months old.
“I feel bad whenever I say this to parents, but it’s all about risk minimisation,” explains Kat. “Yes, your baby is licking keys or the dog, it can be good to expose them to these things – this is called the ‘hygiene hypothesis’. But where we can, and if it's easy enough to do, we should reduce the risk of them being unwell when they’re so little.”
How to store sterilised baby bottles
Your baby’s bottles will stay sterile for 24 hours, keeping them in a clean, covered container with a lid in the fridge or in the steriliser is a good way to store them.
How to wash baby bottles
The best way to clean baby bottles is to wash them by hand with hot soapy water. Then either air dry them, or dry them with a clean cloth or paper towel, says Kat. Disassemble all the parts first, including pulling the teat out of its screw cap. “Use a bottle brush and a teat brush,” she advises.
“You can use a dishwasher but check that your specific bottles are dishwasher safe. Keep in mind, a dishwasher won’t necessarily clean the teat properly, and sometimes the silicone and plastic can take on the fragrances of the soap. Be sure to rinse all your baby bottle components super well in clean water, even when hand washing.”