✔️ Always start by reading the preparation instructions on your formula can.
✔️ In Australia and New Zealand, the guidelines recommend using boiled water that has cooled to around body temperature — approximately 37°C. This should feel warm (not hot) when tested.
✔️ Using water that is too hot can pose a burn risk to both you and your baby. It may also damage essential vitamins and probiotics in the formula.
✔️ Most formula mixes better when the water is warm, not cold. Proper mixing is important to ensure your baby receives the correct nutrition.
✔️ Some overseas sources, such as those from the UK or US, may recommend using water at 70°C to prepare formula. However, this is not recommended by Australian or New Zealand guidelines, or reflected on local product labels. Try not to get confused by international advice.

Why the difference? Health experts across countries have slightly different approaches — it's not that one is wrong, just based on differing opinions or priorities. 

1. Start with Boiled Water

Always boil tap water before using it to prepare formula — even if you'll be warming it later. This is especially important for younger babies.

2. If Water Is Too Hot

✔️ Cool the bottle under running cold water or place it in a bowl of cool water.

✔️ You can also wrap the bottle in a damp cloth and place it in the fridge or freezer briefly (watch closely to avoid overcooling).

3. Mix Boiled and Cooled (Preboiled) Water

A handy method for getting it just right

✔️ Half-fill sterilised bottles with freshly boiled water and seal them.
✔️ When it's time to feed, top up with additional freshly boiled water to reach the correct volume.
✔️ Test the temperature before using the water to prepare formula.  

4. Keeping Water Warm in a Thermos

✔️ Store freshly boiled water in a clean, insulated thermos to keep it warm for later use.    
✔️ Test the temperature before using the water to prepare formula.

5. Using a Microwave

It’s fine to use a microwave to heat water.
✔️ Use a microwave-safe container.
✔️ Heat in short bursts and stir.
✔️ Test the temperature before using the water to prepare formula.

Accurate Measurement Matters

Taking a little extra time to measure water accurately is important—especially for young babies or those with health concerns. Using too much or too little water can lead to constipation, dehydration, or electrolyte imbalances, all of which can make your baby unwell. Only change the water-to-powder ratio if your healthcare professional specifically advises it for your baby’s needs.

Always follow the water-to-powder ratio instructions on your formula tin

While this might seem obvious, it’s easy to overlook. Each formula is carefully designed to provide the right nutrition, and the correct dilution is based on matching the nutrients found in breastmilk. Because scoop sizes and instructions can vary between brands and stages, always check the label for a new product before preparing a bottle.

Tips for Measuring Water Correctly:

✔️Measure Water First:  Always pour and measure the water before adding formula powder.

✔️Understand Bottle Markings: Most baby bottles have measurement markers every 10mL between the main numbered lines. For example, if your bottle shows 120mL and 150mL, and there are two evenly spaced dots in between, these usually indicate 130mL & 140mL.

✔️Check at Eye Level: To ensure accuracy, make sure the water line is exactly at the marker when viewed at eye level. 

✔️Double-Check if Needed: Remember, bottle measurements can sometimes be a little off. For extra accuracy, you can weigh the water or use a separate measuring jug. Ensure the container on the scales is accounted for. Note that some household scales may be inaccurate, so use a reliable device.

Accurate Measurement Matters

Taking a little extra time to measure powder accurately is important—especially for young babies or those with health concerns. Using too much or too little powder can lead to constipation, dehydration, or electrolyte imbalances, all of which can make your baby unwell. Only change the water-to-powder ratio if your healthcare professional specifically advises it for your baby’s needs.

Always follow the water-to-powder ratio instructions on your formula tin

While this might seem obvious, it’s easy to overlook. Each formula is carefully designed to provide the right nutrition, and the correct dilution is based on matching the nutrients found in breastmilk. Because scoop sizes and instructions can vary between brands and stages, always check the label for a new product before preparing a bottle.

Tips to measure the right amount of formula:

✔️ Use the scoop provided with the formula can: Never use a scoop from a different formula tin, such as from a different brand or stage, because the scoop size varies depending on the formula and proportions required.

✔️Follow Label Directions: Adhere to the feeding guide on the can for the recommended powder-to-water ratio.

✔️Ensure a full but not packed scoop: Fill the scoop with powder, ensuring it’s full but not compressed.

✔️Precisely Level Off the Powder: Many formula cans have an inbuilt lip to facilitate levelling off the powder. If not, use a clean, dry knife for precise levelling.

✔️ Optional Double Check Weight of Grams per Scoop: Every formula label indicates the grams of powder in one scoop, so it is possible to check. If you have scales that measure accurately to 0.1g, you can verify the weight. Ensure the container on the scales is accounted for. Note that some household scales may be inaccurate, so use a reliable device.

✔️ Swirl or Stir: Instead of shaking, opt for swirling or stirring the formula. While this method may take longer, it ensures thorough mixing without excess bubbles.

✔️Tapping: Tap the bottom of a bottle against the bench to help force bubbles to rise to the top, facilitating their removal.

✔️Allow Time to Settle: Let the formula sit for a bit before feeding to allow some time for bubbles to dissipate. Even a few minutes will help, or leaving in the fridge for a few hours.

Always pour water in first, for two main reasons:

✔️ Firstly, as it means you can measure the water accurately when using the bottle measurements.

✔️ Secondly, this also helps with dispersion of power in the water & prevents the powder clumping on the sides or bottom of the bottle.

Yes, you can make formula in bulk. However, it is recommended to make formula individually rather than in bulk.

Recommendations:

➡️ The Australian Infant Feeding Guidelines recommend preparing only one bottle at a time, just before feeding. This is because it is safest for formula to be made just before using, as bacteria does not have time to grow. Additionally, preparing bottles individually ensures accuracy in accordance to the feeding guide on the formula label.

➡️ The labels of formula also advise that each bottle should be prepared individually. 

Consideration if Making Formula in Bulk

While not recommended, it is possible to prepare formula in bulk often using a pitcher for convenience. This method is used overseas such as in the US. 

✔️ Maintain Correct Dilution: It is crucial to maintain the correct powder-to-water dilution ratio specified on the label. This may require careful calculations. If unsure, consult a healthcare professional or contact the customer enquiry line of the product for guidance.

✔️ Ensure it is Refrigerated Correctly: Any prepared formula kept in the fridge must be used within a 24 hours period. Therefore, ensure that the amount made will be used within this time. 

Safe Timeframes for Using Warm or Room Temperature Formula: 

➡️ Australian Guidelines (2013)
According to the Australian Infant Feeding Guidelines, prepared formula should be used within 1 hour if kept at room temperature and not refrigerated. Discard any unused formula after this time.

➡️ New Zealand Guidelines (2021)
The New Zealand Healthy Eating Guidelines recommend using formula within 2 hours of preparation if left at room temperature. Any remaining formula should be discarded after this time.

➡️ Product label regulations Australia and New Zealand (updated 2024 with full safety assessment undertaken) require labels to state that formula left in the bottle after a feed must be discarded within 2 hours. 

Other organisations such as overseas US CDC advise:
– 1 hour if the formula has touched baby’s lips
– 2 hours if the bottle was untouched, was time of preparation.

What Should Parents Do?

To stay on the safe side:
✔️ Use formula as soon as possible after it’s prepared.
✔️ Follow the more cautious 1-hour timeframe if you’re unsure, especially in hot weather (over 32degrees) or when feeding newborns, premature babies, or those with weaker immune systems.
✔️ If the bottle hasn’t been used, it can be refrigerated within 1 hour for later use.
✔️If the bottle has been used for feeding, always discard any leftover formula within 2 hours of when it was prepared.

Yes — prepared formula can be safely stored in the fridge for up to 24 hours. 

What the guidelines say:

According to the Australian Infant Feeding Guidelines, NZ Healthy Eating Guidelines, and formula labelling standards, storing prepared formula in the fridge for up to 24 hours is considered safe — as long as it’s done correctly.

Key safety tips:

✔️ Fresh is best: It’s always safest to prepare formula fresh and use it immediately, as this reduces the risk of bacteria growing.
✔️ Check your fridge: Ensure your fridge is set between 0°C and 4°C. Older fridges may not stay cold enough, so it's a good idea to use a fridge thermometer to check. 
✔️ Refrigerate immediately: As soon as the formula is prepared, place it in the fridge right away. The bottom shelf at the back is best, as it’s usually the coldest spot.
✔️ Don’t refrigerate used bottles: If formula has been left out at room temperature for over an hour, or if your baby has already fed from the bottle, it should not be stored — discard it.
✔️ Label and track: Note the date and time the formula was made. Use a sticker on the bottle, or take a note on the fridge to keep track.
✔️ Use within 24 hours: Even in the fridge, bacteria can still grow slowly. Any formula older than 24 hours should be thrown out.

Note: Some formulas — such as thickened reflux formulas — are not suitable for refrigeration, as cooling can affect their consistency and texture.

No — but many babies prefer it.

While babies can safely drink formula at room temperature, many accept it more easily when it’s warmed slightly.

✔️ Skipping or lightly warming formula can save time and make feeding more convenient. 

✔️ Try offering formula at room temperature or even chilled from the fridge (this may be more accepted in warmer weather or as your baby gets older) to see what your baby prefers^.

▶️ Keep in mind that formula typically mixes best with warm water, as stated on the label. This may vary slightly between brands, so it’s worth experimenting.
▶️ Specialty formulas, like thickened reflux formulas, may need to be warmed to maintain proper texture and prevent separation.

1. Use Hot Water

• Place the bottle in a bowl of hot water for a few minutes (usually less than 10 minutes).

• Alternatively, run hot tap water over the bottle until the milk feels warm.

• Always test the temperature by placing a few drops on the inside of your wrist — it should feel lukewarm, not hot. A baby’s mouth is very sensitive and can burn easily.

2. Use Bottle Warmers

Most bottle warmers take about 10 minutes to heat the milk to a consistent temperature.

Some models wrap around the bottle; others make direct contact with the milk and may need to be cleaned after use.

Follow the manufacturer’s instructions for best results and safety.

3. Microwave (Not Recommended)

Microwaving is not advised due to safety and nutritional concerns, including:

❌ Uneven heating: Microwaves can cause hot spots that may burn your baby’s mouth or throat.

❌ Nutrient loss: Overheating can damage important nutrients like vitamins and probiotics.

❌ Bottle safety: Not all bottles are microwave-safe. Some plastics may release harmful substances when heated.

If you still have to use a microwave, you need to take extra care:

• Use a low power setting and heat in short bursts (~ 20 seconds)

• Shake the bottle well after heating to help distribute heat evenly — but be aware that clumps of powder or fat can still cause hot spots. 

• Let the milk sit for 1 minute to allow the temperature to even out.  

• Always test the milk temperature on your wrist before feeding.

Boiling tap water is recommended and is especially important in the early months.

Babies have developing immune systems, which makes them more vulnerable to microorganisms that can occasionally be present in tap water. Boiling helps reduce this risk, particularly for babies under 3 months or those with health concerns.

Current Recommendations:

Australia: Boil tap water for formula preparation until your baby is 12 months old. 

New Zealand:

► Boil public tap water (e.g. treated city water) until your baby is 6 months old.

► Boil private water sources (e.g. tank or bore water) until 18 months old.

Note: Boiling removes bacteria and microorganisms, but it does not eliminate other potential contaminants, such as nitrates or lead. 

Private water (such as rural tank water) may come from rainwater, bores, or streams, and is often stored, transported, and treated in different ways. Although it’s normally considered safe, the quality can vary greatly, so each situation should be assessed individually.

Things to Consider:
► Unlike public water, private water is not routinely monitored, tested, or treated. This means there’s a higher risk it may not always be safe for preparing infant formula.

► Contamination can occur from various sources, including:
‣ Lead paint on roofs used to collect rainwater
‣ Dirty gutters (e.g. bird droppings, dead animals, rotting leaves)
‣ Pesticides, fertilisers, or animal waste seeping into soil (for bore or stream water)
‣ Unclean water tanks
‣ Household plumbing and pipes

► Even if water has been filtered or treated, contaminants from older lead pipes may still be present — especially if water has been sitting overnight.

Tip: In the morning, run the tap for 10–15 seconds before using the water for formula. This helps flush out potential contaminants from pipes.

Also, review the FAQ for boiling tap water. 

Yes

According to the Australian Infant Feeding Guidelines:

“Bottled water (but not sparkling mineral water or soda water) can be used to prepare formula if unopened, but it is not necessary.”

Sealed bottled water is manufactured under strict quality controls and therefore is very safe. However, it’s generally advised to boil it first—especially for babies under 3 months old or with health concerns.  

 ✔️ Always check the label for specific storage instructions from the manufacturer.

✔️ Keep the formula in its original tin for hygiene.

✔️ Store in a cool, dry place like a pantry or food cupboard—never in the fridge, as moisture can spoil the powder.

✔️ Make sure the scoop is clean and dry before and after each use. Avoid placing it on benches or other surfaces—return it directly to the tin. If it becomes wet or dirty, wash and dry it thoroughly before putting it back.

✔️Reseal the lid promptly after each use to avoid contamination.

✔️ Keep the tin away from water or steam to avoid moisture entering the powder.

There’s no official recommendation, but here’s what to keep in mind:

  ► Powder in a dispenser is more likely to be exposed to air, light, heat and moisture than when stored in its original tin. This can cause nutrients to degrade more quickly.

  ► The usual 3–4 week guideline on formula tins (after opening) does not apply to powder kept in a dispenser.

  ► To keep the formula as fresh and safe as possible, use powder from a dispenser as soon as you can—ideally within a few days, not weeks.

Sterilising is most important for babies under 3 months or those who are immune compromised, as they are more vulnerable.

In Australia, sterilising bottles is recommended for up to 12 months of age.

In New Zealand, it is recommended to sterilise bottles until your baby is at least 6 months old. 

There are 5 main methods for sterilising bottles.

1. Electric Steam Sterilisation

2. Microwave Steam Sterilisation

3. Cold Water Antibacterial Sterilisation

4. Boiling (Traditional Method)

5. UVC Sterilisation

You can find detailed information on each method in our article on cleaning and sterilising baby bottles .