How to Sterilise Baby Bottles: How Often, When to Stop, and Best Methods
- Samantha Pieterse
- Jan 30, 2024
- 12 min read
Updated: 22 hours ago
Sterilising baby bottles and feeding equipment is one of those topics that sounds straightforward until you actually become a parent. Then suddenly you’re hearing different advice from family, friends, clinics, and social media. Some say you must sterilise after every feed, others say it’s unnecessary, and many parents are left wondering what’s genuinely protective for their baby and what’s just adding pressure during an already exhausting stage.
In the early months, your baby’s immune system is still developing, which is why hygiene around feeding equipment is very important. Bottles, teats, dummies, pump parts, and nipple shields come into direct contact with your baby’s mouth and milk, creating an environment where germs can grow if cleaning and sterilising aren’t done properly. At the same time, over-sterilising or using the wrong methods can also raise questions about practicality, and everyday life with a baby.
This guide will look at everything you're wondering about sterilising baby equipment, why recommendations change as your baby grows, and how to approach it in a way that protects your baby without overwhelming you. Whether you’re using boiling water, a steam steriliser, or managing without electricity or consistent hot water, understanding the reasoning behind the advice helps you make calm, confident choices that fit your family.
Why Do You Need to Sterilise Baby Bottles and Feeding Equipment?
In the first weeks and months of life, your baby’s immune system is still finding its feet. Newborns haven’t yet built up the antibodies and gut protection that older babies and adults rely on to deal with everyday germs. This makes them more vulnerable to infections that might seem minor to us but can cause real problems for a young baby, especially tummy bugs that lead to vomiting, diarrhoea, and dehydration.
Feeding equipment creates the perfect environment for germs to grow if it isn’t cleaned properly. Milk, whether breastmilk or formula, leaves behind tiny residues that bacteria and yeast love. Bottles, teats, dummies, and breast pump parts come into direct contact with your baby’s mouth and digestive system, so anything growing on those surfaces has a very easy path into their body. Germs such as bacteria, viruses, and yeast can multiply quickly, even when the equipment looks clean to the naked eye.
This is why hygiene around feeding equipment matters more than general household cleaning, especially in the early stages. Wiping surfaces or rinsing bottles is not enough in the newborn stage.
Sterilising, after proper washing, reduces the number of germs to a level that a young baby’s immune system is better able to cope with. As your baby grows and their immune system matures, this balance changes, but in the early months, sterilising bottles and feeding equipment is one of the simplest ways to lower the risk of avoidable infections and give your baby a safer start.
What Can Happen If Baby Bottles and Feeding Equipment Aren’t Sterilised Properly?
When feeding equipment isn’t sterilised properly in the early months, the biggest concern is that germs can slip past a baby’s still learning immune system. This most often causes tummy upsets, frequent loose stools, vomiting, or feeding intolerance. In a small baby, even mild stomach bugs can quickly lead to dehydration, simply because they have very little fluid reserve to fall back on.
Newborns, premature babies, and babies who have recently been unwell are especially sensitive. Their bodies are not yet as good at containing infections, so something that might cause a day of discomfort in an older child can become more serious much faster in early infancy. This is why health professionals tend to be more cautious about feeding hygiene during this stage, even if everything else in the home feels clean.
What often catches parents off guard is that problems don’t always look dramatic at first. Subtle signs like increased wind, unsettled feeds, slower weight gain, or recurring mouth or nappy issues can sometimes be linked back to feeding hygiene. Sterilising bottles and equipment doesn’t guarantee a baby will never get sick, but it lowers the chances of preventable infections during a time when even small illnesses can feel big for both baby and parents.
How to Sterilise Baby Bottles and Equipment
There are a few safe, reliable ways to sterilise baby bottles and feeding equipment, and the right option often depends on what you have access to and how often you’re feeding. What matters most is that the method is used correctly and consistently. Before looking at the different options, there’s one step that never changes.
Before You Sterilise: Cleaning vs Sterilising
Cleaning always comes first. Sterilising does not work properly if bottles and parts still have milk residue on them.
All bottles, teats, dummies, and breast pump parts should be washed thoroughly in warm, soapy water straight after use. Use a bottle brush to reach into corners and around teat rims, then rinse well under clean running water. A dishwasher can also be used for cleaning if items are labelled dishwasher safe.
Once the equipment is visibly clean, sterilising is the step that reduces remaining germs. Skipping the cleaning stage makes sterilising far less effective.
Sterilising Baby Bottles Using Steam (Microwave or Electric)
Steam sterilising is one of the most commonly used methods for everyday feeding equipment.
Clean bottles and parts are placed into a microwave or electric steriliser with a small amount of water. As the water heats, it produces steam, which reaches a high temperature and sterilises the equipment.
This method is popular because it is quick, chemical-free, and easy to use at home. Many sterilisers also keep bottles sterile for up to 24 hours if the lid remains closed.
When using steam sterilisers, always open the lid away from your face, as the steam can be very hot. It’s also important to regularly clean the steriliser itself, as moisture trapped inside can encourage mould growth over time.
Sterilising Baby Bottles in Boiling Water
Boiling is a simple and effective method that does not require special equipment.
After cleaning, fully submerge bottles and parts in a large pot of water. Bring the water to a rolling boil and keep it boiling for at least five minutes. Make sure all items stay underwater and are not touching the sides of the pot.
Remove equipment with clean tongs and allow it to air dry on a clean surface or leave it in the covered pot until needed. Some plastic bottles and teats can wear out faster with frequent boiling, so always check the manufacturer’s instructions and replace items that show signs of damage.
Sterilising Baby Bottles Without a Steriliser
If you don’t have access to a steam steriliser, boiling water remains the best alternative.
This is especially useful during load shedding, travel, or times when electricity is unreliable. As long as clean water and a heat source are available, boiling provides a dependable way to sterilise feeding equipment.
Planning ahead can help, for example sterilising several bottles at once and storing them correctly until needed.
Cold Water Sterilising Solutions (When and How to Use Them)
Cold water sterilising uses a chemical solution dissolved in water to sterilise bottles and equipment.
Items are placed in the solution for the required time, usually around fifteen minutes, and can remain submerged for up to twenty-four hours. This method can be helpful when travelling or when heat-based methods are not practical.
Cold sterilising solutions are best used as a backup rather than a daily routine. Some babies are sensitive to residual taste or smell if items are not handled properly, and frequent use may disrupt the natural balance in a baby’s mouth. If used, follow instructions carefully and avoid unnecessary overuse.
Can You Sterilise Baby Bottles in the Dishwasher?
Dishwashers can clean baby bottles very well, but they do not always fully sterilise them.
If bottles and parts are dishwasher-safe, use the hottest wash cycle with a heated-dry setting, ideally reaching temperatures above 65°C. Place smaller items in a secure basket so they don’t move around.
Dishwashers are often suitable for cleaning older babies’ equipment, or for use as part of a routine once sterilising requirements are less strict. For young babies, dishwashers should be viewed as a cleaning step rather than a replacement for proper sterilisation.
Is One Sterilising Method Better Than Another?
From a safety point of view, all recognised sterilising methods can reduce harmful germs when they’re used correctly. The difference lies in how they work, how often they’re needed, and how gentle they are for everyday use. This is where heat-based methods and chemical methods start to separate.
Steam sterilising and boiling rely on heat to do the job. High temperatures reliably kill germs without leaving anything behind on the bottles or teats. For this reason, heat-based methods are generally preferred for daily use, especially in the first few months. They are predictable, chemical-free, and easy to repeat as part of a routine. For most families, steam or boiling strikes a good balance between safety and practicality.
Cold water sterilising solutions work differently. They are effective, but they don’t distinguish between harmful germs and some of the helpful bacteria that naturally live in a baby’s mouth. While occasional use is unlikely to cause problems, frequent reliance on chemical solutions may interfere with this balance in some babies. That’s why these products are best kept for specific situations, such as travel, power outages, or times when heat simply isn’t available.
The most sensible approach is to use the right method at the right time. For everyday feeding at home, heat-based sterilising is usually the most straightforward option. When convenience or circumstances take over, having a safe backup method is far better than skipping sterilising altogether.
Do You Need to Sterilise Baby Bottles After Every Use?
This is one of the questions parents wonder about most often, especially in those early, sleep-deprived weeks. The honest answer is that it depends on your baby’s age and health, and on what’s realistically possible in your day-to-day routine.
During the newborn phase, particularly in the first two to three months, sterilising feeding equipment more frequently is recommended. As babies grow and their immune systems strengthen, the balance starts to shift. Washing bottles and feeding equipment properly straight after use becomes the most important step, and sterilising can move to a less frequent routine.
How Often Should You Sterilise Baby Bottles by Age?
How often you need to sterilise baby bottles changes as your baby grows. Age is important because your baby’s immune system, feeding patterns, and environment all change over time. A staged approach helps parents stay realistic while still keeping feeding equipment safe.
0–3 Months
This is the period where sterilising is most important. During the first few months, feeding equipment should ideally be sterilised after every use. If that isn’t manageable, thoroughly cleaning bottles after each feed and sterilising them in batches at least once or twice a day is a practical alternative for many families.
Consistency is more important than timing. Whether you sterilise immediately or as part of your daily routine, the goal is to ensure bottles and teats are regularly sterilised during this early stage.
3–6 Months
As babies move past the three-month mark, many parents can begin to ease up slightly. Washing bottles and feeding equipment promptly after each feed becomes the priority, with sterilising usually reduced to once a day for healthy babies.
This stage often includes more outings, childcare support, or the use of expressed milk, so attention to cleaning remains important. Sterilising still plays a role, but it no longer needs to dominate the routine.
6–12 Months
By this stage, most babies are eating solids, crawling, and exploring the world with their mouths. Their immune systems are more mature, and feeding equipment hygiene is shifting toward thorough cleaning rather than strict sterilisation.
For many families, sterilising becomes optional between six and twelve months, particularly for healthy babies with no underlying concerns. Some parents choose to stop altogether, while others continue occasionally, especially after illness or during periods where hygiene may be harder to control. Both approaches can be appropriate depending on your baby and your circumstances.
When Can You Stop Sterilising Baby Bottles?
For most healthy babies, sterilising bottles and feeding equipment can be stopped by around twelve months of age. By this stage, your baby’s immune system is far more mature, they are eating a wide range of foods, and their everyday exposure to germs is already much higher than it was in early infancy. At this point, thorough washing with hot, soapy water is sufficient to keep the feeding equipment safe.
The reason many guidelines use the 12-month mark is not that something changes overnight, but that it reflects a gradual shift in risk. As babies grow, their bodies become better at handling everyday bacteria, and strict sterilisation offers little additional benefit. For many families, sterilising has already been phased out naturally by this stage, without any negative effects.
That said, there isn’t a single rule that fits every baby. Some children benefit from continuing sterilising for longer, either full-time or in certain situations, and that choice can be made based on individual circumstances.
Situations Where You Should Keep Sterilising Longer
You may want to continue sterilising baby bottles and feeding equipment beyond twelve months if your baby was born prematurely or has ongoing health concerns that affect their immune system.
Babies who experience frequent infections, particularly in the first year, may also benefit from a longer sterilisation period as an added precaution.
If your baby is formula-fed, continuing to sterilise for longer can be helpful, especially during the first year, as formula preparation requires careful hygiene.
In homes where access to clean running water or consistent electricity is unreliable, continuing to sterilise feeding equipment can provide extra reassurance and protection, even beyond infancy.
Stopping sterilising is not a deadline to rush toward. It’s a gradual decision that can be adjusted to suit your baby, your home, and your peace of mind.
How Long Do Sterilised Baby Bottles Stay Sterile?
Once baby bottles and feeding equipment have been properly sterilised, they can stay sterile for up to 24 hours, as long as they are handled and stored correctly. The timing itself is less important than what happens after sterilising.
Sterility is easily lost through contact, moisture, or air exposure. Understanding how to handle and store bottles after sterilising helps parents plan feeds more easily and reduces unnecessary re-sterilising.
What Breaks Sterility After Sterilising?
Sterilised bottles are no longer sterile if the inside of the bottle, the teat, or any surface that comes into contact with milk is touched.
Using a cloth or towel to dry bottles can introduce new bacteria, even if the cloth looks clean. Moisture left inside bottles or teats also creates an environment where germs can settle.
How to Keep Bottles Sterile After Sterilising
Avoid touching the inside of bottles or teats. Hold bottles by the base or neck ring, and teats by the outer rim or plastic screw cap.
Allow bottles and teats to air-dry completely in a clean area. Do not wipe them with a towel or cloth.
Store bottles upside down to prevent moisture from collecting inside and to protect the opening from airborne contaminants.
Where Should You Store Sterilised Baby Bottles?
Sterilised bottles should be stored in a clean, sealed container made of glass or BPA-free plastic. This keeps them protected until they are ready for use.
If possible, storing sterilised bottles in the fridge can help slow bacterial growth, which is especially useful during hot weather or load shedding when room temperatures rise. Freezing sterilised bottles is not necessary unless they are being stored with expressed breastmilk.
If you are using a steriliser with a built-in lid, bottles can often be left inside until needed. Try to open the steriliser as little as possible to keep the inside environment clean.
Final Thoughts on Sterilising Bottles
Sterilising baby bottles can feel like one more thing to get right in a season where you’re already juggling a lot. The truth is, you don’t need to be perfect for your baby to be safe and well cared for. Consistent, thoughtful hygiene matters far more than flawless rule-following.
As your baby grows, routines naturally change. What feels non-negotiable in the early weeks often becomes more relaxed over time, and that’s okay. Understanding why advice changes helps take the fear out of letting go of strict habits and replacing them with confidence in your own judgment.
Sterilising is a supportive tool, not a test of good parenting. When you understand the reasoning behind the recommendations, it becomes easier to make calm, informed choices that fit your baby, your home, and your day-to-day life.
Need personalised advice about your baby’s feeding routine?
If you’re unsure what’s appropriate for your baby’s age and health, we’re happy to help.
👉 Book a check-up with us at Mums & Bums in Rooihuiskraal and let’s talk through what works best for your family.
Frequently Asked Questions About Sterilising Baby Bottles
Do I need to sterilise baby bottles every time?
In the first few months, sterilising baby bottles regularly is recommended. As babies grow and their immune systems mature, thorough washing after each feed becomes more important, and sterilising can be done less often.
How often should I sterilise baby bottles?
For newborns, bottles are usually sterilised after every use. From around three months, many parents sterilise once a day, provided bottles and equipment are washed properly after each feed.
When can I stop sterilising baby bottles?
Most guidelines suggest you can stop sterilising baby bottles by around 12 months of age for healthy babies. At this stage, careful washing with hot, soapy water is usually sufficient.
Can I stop sterilising baby bottles at 6 months?
Some parents begin phasing out sterilising between 6 and 12 months, especially if their baby is healthy and starting solids. Others choose to continue longer. Both approaches can be appropriate depending on individual circumstances.
How long do sterilised baby bottles stay sterile?
Sterilised baby bottles can remain sterile for up to 24 hours if handled correctly and stored in a clean, sealed container, without touching the inside surfaces.
Can I sterilise baby bottles without a steriliser?
Yes. Boiling baby bottles in water for at least five minutes is an effective way to sterilise bottles if you don’t have access to a steam steriliser, such as during travel or load shedding.
Is a dishwasher enough to sterilise baby bottles?
Dishwashers can clean baby bottles very well, but they do not always fully sterilise them. A hot wash cycle above 65°C helps reduce germs, but young babies may still benefit from additional sterilising.
Is sterilising baby bottles really necessary?
Sterilising baby bottles is most important in early infancy, when babies are more vulnerable. As babies grow, the focus shifts toward good cleaning practices rather than strict sterilising.
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