When Can You Stop Sterilising Baby Bottles?
Sterilising is one of those newborn jobs that feels endless in month two and slightly absurd by month ten, which is why the question comes up so often. The New Zealand and Australian answer is clearer than the internet suggests.
The short answer
The usual guidance in New Zealand & Australia is to keep sterilising baby bottles until your baby is 12 months old. That is the same age at which bottles themselves are generally phased out, so for most families the two changes happen together rather than one after the other.
If you are wondering when you can stop sterilising baby bottles, 12 months is the number to plan around, with the caveats below.
Why 12 months, and not sooner
A baby's immune system is still developing through the first year, and milk is a medium that bacteria grow in readily, particularly when a bottle sits warm for a while. Sterilising removes the organisms that ordinary washing can leave behind in places that are difficult to reach, such as the inside of a teat.
As babies get older and start putting a great many other things in their mouths, the marginal benefit of sterilising drops. That is the practical logic behind the first birthday as a cut-off rather than an earlier one.
Formula and expressed breastmilk are treated differently
This is the distinction most often missed, and it changes the workload significantly.
- If you are using formula, sterilising bottles and feeding equipment is important, because powdered formula is not a sterile product.
- If you are feeding expressed breastmilk, cleaning with warm soapy water is usually enough.
That is a meaningful difference for anyone expressing, and it is worth checking with your child health nurse for your own situation rather than applying the strictest rule by default.
When to keep sterilising regardless of age
Pregnancy, Birth and Baby advises speaking to your doctor or child health nurse about cleaning bottles and expressing equipment if:
- Your baby is sick
- Your baby was born premature
- You have any type of infection on either of your breasts or nipples
In these situations, follow the advice you are given rather than the general timeline.
How to sterilise baby bottles properly
Whatever method you use, the sequence matters more than the equipment.
Step one: clean first
Sterilising is not a substitute for washing. Take everything apart, including teats, rings and valves, and wash in hot soapy water with a bottle brush. Milk residue left behind will survive the sterilising step underneath it.
Clean after every feed. If you cannot get to it straight away, rinse with clean water so it is easier to clean properly later.
Step two: choose a method
- Boiling. Submerge the items fully in a large pot of boiling water, keeping teats from touching the base. Simple, and needs nothing you do not already own.
- Steam. Electric or microwave steam units are quick and remove the guesswork.
- Cold water solution. Sterilising tablets or liquid in a container, with everything fully submerged and no trapped air bubbles.
Check what your bottles are made of before choosing. Silicone and glass handle heat well, and our baby bottle range is designed to be sterilised by the usual methods.
Step three: store them properly
This is where the effort is most often wasted. Leave items in the steriliser or covered container until you need them. If you take them out, assemble the bottles fully so the inside surfaces are not exposed, and handle them with clean hands.
A sterilised bottle left open on a bench is no longer sterile, which is worth knowing before you do a whole batch in advance.
What else needs sterilising
Bottles are the obvious one. The rest of the kit is easy to forget.
- Teats, rings and caps, taken apart rather than sterilised assembled
- Breast pump parts that touch milk
- Milk collectors and storage containers
- Dummies, if you use them
Our cleaning and hygiene accessories range covers brushes, drying racks and the accessories that make this routine faster, and pump accessories covers replacement parts for pumps.
Signs it is time to replace rather than sterilise
Repeated sterilising is hard on equipment, and worn parts are a hygiene issue in their own right. Pregnancy, Birth and Baby advises replacing bottles, teats and feeding equipment as they show signs of wear.
- Teats that have become sticky, swollen, thinned or discoloured
- Cracks, cloudiness or scratches inside bottles, which trap residue
- Valves or membranes that no longer sit flat
Frequently asked questions
When can I stop sterilising baby bottles?
Australian & New Zealand guidance recommends sterilising until your baby is 12 months old. Bottles themselves are generally phased out at around the same age.
Do I need to sterilise if I only feed expressed breastmilk?
Cleaning with warm soapy water is usually enough for expressed breastmilk, while sterilising is important when using formula. Check with your child health nurse if your baby is unwell, was premature, or if you have a breast or nipple infection.
How do I store sterilised bottles?
Leave them in the steriliser or a covered container until needed, or assemble them fully so the inside surfaces stay protected. Handle with clean hands. An open bottle sitting on a bench does not stay sterile.
Is a dishwasher enough?
A hot dishwasher cycle cleans well, and cleaning is a separate step from sterilising. If you are using formula, sterilise after washing rather than treating the dishwasher as the whole process.
What about bottles that have been sitting out after a feed?
Throw away any formula or expressed breastmilk left at the end of a feed, or after one hour. Then wash the bottle, or rinse it with clean water if you cannot wash it right away.
The short version
Sterilise until 12 months, clean after every feed, take everything apart before washing, and store sterilised items covered or assembled. If you are feeding expressed breastmilk rather than formula, warm soapy water is usually enough.
If you are not sure how to care for a particular Haakaa product, get in touch and we can talk you through it.
