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The product should not be heated in the bottle. Warm milk is an excellent breeding ground for bacteria, so once a bottle of powder has been prepared and heated, it should be used within an hour and all leftovers must be discarded. The best way to use a bottle is to fill it with boiling water only – which a good bottle keeps above 70 ° C for four to six hours – and then make each bottle better when your child is hungry.
Whether you’re getting ready for the day, on a long drive, or traveling with a bottle-fed baby, this is one of the most common questions Australian mums ask – and doing it right will keep your baby safe and well-fed. Here’s exactly how long it takes to warm up, why a hot water bottle is a smart option, and how to take care of feeds when you’re out and about.
Short answer
There are two hidden questions in it “how long does the oil mixture stay warm in the bottle?”
- Heat production formula: Not acceptable at all. Once mixed and heated, use internally one hourthen throw it away. Bacteria multiply rapidly in warm milk.
- To store hot water in a bottle to make a scrub later: This is a safe method. A good sealed bottle will keep water above 70°C on average four to six hourswhich is hot enough to mix the powder whenever you want.
In short: the bottle is la waternot finished bottles of milk.
Why heating formula is dangerous
Powdered baby food is not sterile, nor is the environment in which it is made. Bacteria present can multiply rapidly. This is why Australian health guidelines are careful about how long a prepared bottle can be left out, and strongly recommend that bottles not be heated for long periods of time.
The Raising Children Network recommends making mixed foods whenever possible, and warns that heating a bottle for long periods of time can cause bacteria to grow. As a rule of thumb, don’t let the bottle heat for more than 10 minutes, and don’t use the product at hot temperatures in the bottle or insulated bag for hours.
How long are reheated recipes safe?
As soon as you make and heat the bottle, the clock starts. General guidelines for Australia are:
- Warming and delivery of the child: work inside 1 hour. If your baby starts to drink, throw away anything left after feeding – saliva harbors bacteria.
- Produced and stored at room temperature (not heated): work inside 2 hours.
- It is prepared and stored immediately in the refrigerator (below 5 ° C): can be stored until 24 hours.
Note that none of this has anything to do with milk storage temperature. Heat is what you want to avoid when mixing.
Safe way: carry hot water, make fresh
A strategy recommended by the Raising Children Network and in line with NHMRC baby feeding guidelines is to keep liquid and powder separate, then combine when your baby is ready to feed. Here’s how to do it while traveling:
- Before you leave, boil fresh water and pour it into a clean, preheated vacuum bottle. Filling the bottle completely and heating it with hot water first helps keep it hot longer.
- Measure out the amount of baking powder you will need in a clean, dry container or water dispenser with separate compartments.
- When it’s time to feed, pour hot water (still 70°C or more) into a sterilized bottle, add flour and mix. Water at 70°C or higher will kill the bacteria in the flour.
- Cool the bottle quickly under cold running water or in a bowl of cold water until it feels warm. Try a few drops on the inside of your hand – it should feel warm, not hot.
This gives you the protection of freshly made milk without the risk of bacteria keeping the milk warm. For more travel tips, check out our guide on how to keep warm while traveling.
How long does a bottle keep hot enough?
A good stainless steel bottle will keep water above 70°C for four to six hours, and at room temperature for longer. A few things make a real difference:
- Pre-heat it. Fill the empty bottle with hot water, put the lid on, wait five minutes, then pour and refill with hot water. This can add an hour or two to the heat storage.
- Write well. A full bottle retains heat better than an empty one.
- Be closed. Every time you open the bottle, heat escapes – so open it at mealtime.
If you’re choosing between a bottle and something else, our comparison of portable bottle warmers and thermos breaks down when everything shines.Browse our range of Baby Bottles – intelligently designed to keep baby’s food warm, ready to drink and easy to nurse, wherever the day takes you.
What about a portable bottle warmer?
A hot water bottle is great for making new bottles, but it won’t warm a bottle of breast milk or a pre-made bottle from the fridge. This is where a portable bottle warmer comes in handy. It heats the bottle to body temperature in minutes without having to pour hot water around – perfect for car journeys, socializing and holidays.
The Kerub Baby Universal Portable Bottle heats breast milk and cooking oil on the go, so you can warm up a very cold bottle instead of trying to heat it for hours. If you often eat in the car, our guide on how to warm a bottle in the car is a must read. Buy bottle warmers →
Safe times at a glance
- Hot water in a vacuum bottle: stays above 70°C for ~4-6 hours (use to make new bottles)
- Heating method, designed: use within an hour, and discard
- Room temperature formula: work within 2 hours
- Method of preparation in the refrigerator (below 5 ° C): up to 24 hours
- Method of remaining after meals: always losing
Frequently asked questions
How can I keep a bottle made of clay warm in a bottle for a few hours?
No. Heating the chemical for many hours allows bacteria to multiply and is not dangerous. Instead, carry hot water in a bottle and refill the bottle when your child is hungry.
How long can the milk be heated before I throw it away?
After heating, use the bottle within one hour. If your baby starts drinking, throw away whatever is left after feeding.
Is it safe to carry a pre-made bottle in a sealed cooler bag?
Yes – but cold, not hot. Make a bottle, cool it in the fridge, then take it cold in an insulated bag with an ice pack and use it within four hours. Heat before eating.
How hot does the water need to be to make it work?
Use water that is 70 ° C or hotter (freshly boiled water left to cool for no more than 30 minutes). This kills the bacteria in the flour. Refrigerate the finished bottle until warm before serving.
How do I know if the bottle is still hot enough to use?
The pre-heated top bottle stays above 70°C for four to six hours. If you are not sure or it has run out, don’t risk it – use freshly boiled water.
Can I warm a bottle in the car with a bottle warmer?
Yes. A portable bottle warmer is a safe way to warm up a frozen or freshly made bottle to keep warm on the go, instead of trying to keep it warm for a long time.