Feeding your little one comes with so many beautiful moments and just as many questions. Whether you're breastfeeding, expressing, formula feeding or a combination of these, a few simple tips can make those early months feel a little less overwhelming.

If you have been searching for breastmilk or formula storage guidelines in Australia, formula feeding tips or information on how long expressed breastmilk lasts, this guide brings the key information together in one place.

Let’s Start With Breastfeeding And Expressing!

Tip 1: How To Remember Which Side You Breastfed Last

When you are running low on sleep or it's the middle of the night, it can be tricky remembering which breast you used last to feed bub. 

Using a hair tie on your wrist or an app can be an easy way to help you remember.

Tip 2: How To Store Breastmilk Safely After Pumping

How long does expressed breastmilk last? As long as breastmilk is untouched by bub, you can store it for:

• 2 hours in a bottle once baby has started feeding

• 6-8 hours at room temperature (around 21°C) 

• 24 hours in a thermos in an insulated lunchbox with an ice pack 

• 3 days in the fridge 

• 6-12 months in the freezer

Important:

• Label containers of breastmilk with the date it was pumped to help you keep track.

• If your doctor recommends fortified breastmilk, that is, breastmilk with powder formula, it’s important to note that once mixed, it only lasts 12-24 hours in the fridge.

• Try to reduce the number of times breastmilk is transferred between containers as the nourishing fat from breastmilk can stick to the different containers.

Tip 3: How To Freeze Breastmilk Safely

Planning to freeze breastmilk? Remember to:

• Freeze it as soon as possible after pumping.

• Leave a space at the top of the bottle/storage bag so there is space for the liquid to expand.

• Place breastmilk in a deep freezer or towards the back to help reduce temperature fluctuations that can occur when you open and close the freezer door.

Tip 4: How To Thaw Frozen Breastmilk Safely

• Avoid thawing breastmilk on the counter as this can increase the risk of foodborne illness. Instead, defrost overnight in the fridge or under warm running water but use immediately. 

• Once thawed, breastmilk keeps for 1-2 hours or 24 hours in the fridge.

• Do not refreeze thawed breastmilk.

• Do not use a microwave to thaw or warm breastmilk as this can lead to uneven heating and increase the risk of burns. Bubs can have cold thawed breastmilk. 

Tip 5: How To Cook With Breastmilk

Breastmilk can be:

• Stirred into soft and scoopable foods like legumes, scrambled eggs, fruit and veggie purees, mashed veggies and porridge.

• Mixed with nut or seed butters (e.g. peanut or tahini) to make a smooth sauce for dipping finger foods.

• Added to smoothies.

• Used in pancake or muffin batter. Heat from cooking can lower the nutritional value of breast milk a little but it is still very nutritious for bub.

• Stirred into cooked food after it has cooled slightly. This may help preserve more of the milk’s heat-sensitive components.

Important: 

• If you need to store food cooked with breastmilk, it can be placed in the fridge for 1-2 days or frozen for a couple of months.

• Always cook with freshly pumped milk.

Let’s Dive Into Formula Feeding!

Tip 6: How To Use The Pitcher Method To Make Things Easier

The pitcher method involves preparing a day’s worth of formula all at once. This helps:

• save time by avoiding multiple preparations throughout the day

• reduce waste as it allows you to pour the amount of formula needed per feed

Important:

• Avoid mixing leftovers from a feed back into the pitcher as bacteria in bub’s saliva can cause the formula to spoil and increase the risk of foodborne illness. 

Tip 7: Why We Avoid Diluting Formula

Prepare formula according to manufacturer’s instructions. Formula is designed to meet the exact nutritional needs of babies, diluting it may result in bub not getting essential vitamins and minerals needed for optimal growth and development. Furthermore, it can lead to dehydration, kidney issues, weight loss and even seizures.

Tip 8: How To Store Prepared Formula Safely

As long as prepared formula is untouched by bub, you can store it for:

• 1 hour after bub has started the feeding

• 2 hours at room temperature (around 21°C)

• 4 hours in a thermos in an insulated lunchbox with an ice pack 

• 24 hours in the fridge 

• not recommended to freeze as it impacts its nutritional value. 

Important: 

• Once bub drinks from the bottle, use the formula within 1 hour. If not consumed by bub by this time, discard the formula, do not place in the fridge, reheat or cook with it.

Tip 9: How To Cook With Formula

It is generally not recommended to cook with prepared formula as it is expensive and needs to be prepared precisely to avoid overfeeding bub. Heating can also decrease the nutritional value of formula.

If you choose to cook with formula, follow the same advice from ‘Tip 5: How To Cook With Breastmilk’.

Foods cooked with formula can last in the fridge for 24 hours and a couple of months in the freezer.

Tip 10: How To Know When To Throw Out Formula

Once opened, a can of powdered formula can last up to 1 month.

Make Nutritious And Easy Recipes With Our 100% Fruit And Veggie Purees!

Our 100% Australian fruit and veggie puree range makes creating nourishing little meals with breastmilk or formula quick and stress-free. 

Take Home Message

Remember, fed is best, and every feed is an opportunity to nourish your little one with love, care and connection.

Whether you're breastfeeding, expressing, formula feeding or doing a combination, these small practical tips can make feeding feel a little bit easier and more manageable along the way.

FAQS

Q1. How long does expressed breastmilk last?

Freshly expressed breastmilk (untouched by bub) can last 6–8 hours at room temperature, up to 3 days in the fridge and 6–12 months in a deep freezer, depending on the storage conditions.

Q2. How long does formula last in the fridge?

Prepared formula (untouched by bub) can last up to 24 hours in the fridge.

Q3. How long is formula safe after feeding starts?

Once bub starts drinking from the bottle, use the formula within 1 hour and discard any leftovers.

Q4. Can you cook with breastmilk?

Yes. Breastmilk can be added to purees, porridge, mashed vegetables, scrambled eggs, legumes, smoothies, pancakes and muffins.

Q5. Can thawed breastmilk be refrozen?

No. Once breastmilk has thawed, it should not be refrozen.

Q6. Can you freeze prepared formula?

It is not recommended to freeze prepared formula as it impacts its nutritional value.

Q7. How long does an open powdered formula last?

An opened tin of powdered formula can generally last up to one month, but always follow the instructions printed on the packaging.

References

• Australian Breastfeeding Association, 2026. Storing expressed breastmilk. Australian Breastfeeding Association. Available at: https://www.breastfeeding.asn.au/resources/storing-ebm [Accessed 27 Jul 2026].

• National Health and Medical Research Council (NHMRC), 2012. Eat for health: Infant feeding guidelines. National Health and Medical Research Council. Available at: https://www.nhmrc.gov.au/about-us/publications/infant-feeding-guidelines-information-health-workers [Accessed 26 Jul 2026].

• Raising Children Network, 2024. Suitable for 0-12 months: Infant formula making, storing and transporting it. Raising Children Network. Available at: https://raisingchildren.net.au/newborns/breastfeeding-bottle-feeding/bottle-feeding/formula-making-storing-transporting [Accessed 27 Jul 2026].