One of the most frequent concerns for new parents is the temperature of their baby’s formula. Is it safe to give your baby cold formula, or should you always warm it up, and what age can babies drink cold formula milk safely?
With various opinions and advice, it can be challenging to know the best choice for your little one. In this blog, I will delve into the nuances of formula temperature. We’ll chat about the benefits of warm milk for your baby, to the potential risks of serving hot milk and also the risks of not preparing it correctly.
Do You Have to Warm Up Formula?
Short answer is no. The American Academy of Pediatrics (AAP) doesn’t specifically state that formula should be warmed up before feeding. It generally comes down to personal preference, both for you and your baby. Some babies prefer a warm bottle, as it mimics the temperature of breast milk. On the other hand, some babies don’t seem to mind cold or room-temperature formula.
I remember well that my eldest daughter would quite happily drink cold formula whereas my youngest daughter would prefer to have a bottle that was a little warmer.
In essence, whether you choose to serve warm formula or cold formula is generally up to you and your baby’s personal preference. Always make sure you make the formula as guided (see below).
What Happens if You Give Your Baby Cold Formula?
While at the moment there is no scientific evidence that indicates cold formula can affect your baby’s health, it’s important to consider how the temperature of your baby’s milk ‘may’ affect the digestive system in young babies. The cold formula is not known to be harmful; but there are a few things to consider;
Does cold formula upset baby’s stomach?
Cold liquids can sometimes cause muscle contractions in the digestive system, leading to stomach discomfort. Some babies might experience minor cramps or a temporary feeling of fullness that could stop them from finishing their bottle. This could lead to them drinking less milk and therefore could affect their weight gain.
Babies have delicate and immature digestive systems, and younger infants, especially those who are only a few months of age, might be more sensitive to changes in temperatures. It might be worth saving the cooler bottles for older babies.
Acceptance by your Baby
Babies, like adults, have personal preferences. While some babies may have no problem with cold milk, or some may even prefer it, others may refuse it or have difficulty switching from warm milk to cold milk if they have never had it before.
If your baby is used to warm formula, suddenly introducing cold formula could lead to fussiness or refusal to feed. Just keep checking as this may be the reason your baby is being fussy with their milk.
Nutritional Content of cold formula
The temperature of the formula doesn’t affect its nutritional value. Whether served cold or warm, the formula will contain the same essential nutrients needed for your baby’s growth and development.
But, it is important to allow the water to cool to 70°C (158°F) before making up the formula as temperatures above this can reduce the quality of the nutritional content of the formula.
*While using warm water is often recommended for preparing formula, there are exceptions depending on the type of formula you are using. Some new formulas include pro and prebiotics, and the manufacturer’s instructions for these may differ. The reason for this is because high temperatures could affect these special ingredients, potentially reducing the benefits. Always consult the manufacturer’s guidelines and speak with your health care provider to ensure you’re preparing the formula in a way that maintains its nutritional value*
Convenience of cold formula
Sometimes, cold formula might be the most convenient option, especially while traveling or during outings. If your baby accepts cold formula without any issues, it can make life easier in certain situations. However, always make sure to store the formula correctly and it shouldn’t be given if left at room temperature for more than 2 hours. following the manufacturer’s guidelines, to maintain its nutritional quality.
How to make up formula
Making up a bottle of formula for your little one might seem daunting. These simplified steps will guide you through the process safely and efficiently. Whether you’re making a bottle in the middle of the night or prepping for the day ahead, these instructions aim to make feeding time as stress-free as possible for both you and your baby.
- Start with Fresh Water: Fill your kettle with at least 1 liter of fresh tap water and bring it to a boil (don’t reuse water that has already boiled)
- Let it Cool: Once boiled, allow the water to cool for no longer than 30 minutes, this will reduce the heat to around 70°C (158°F)
- Set Up: Place the sterilised bottle on your clean surface.
- Measure Hot Water: Follow the manufacturer’s guidelines and pour the required amount of hot water into the bottle.
- Add Formula: Use the scoop provided with the formula to add the appropriate amount of powder to the water in the bottle. Level off the scoop for accurate measurement.
- Secure and Shake: Put the lid on the bottle and roll and shake until the formula is well-mixed.
- Cool Down: To bring the formula to body temperature, run the capped bottle under a cold tap water until it cools to the desired warmth.
- Temperature Check: Before feeding, test the formula by placing a few drops on the inside of your wrist. It should be at body temperature, which means it feels neither hot nor cold.
Both the American Academy of Pediatrics, the NHS , and formula manufacturers provide guidelines for the storage of infant formula. Here’s some quick tips on times for storing formula;
- 2 hours – A bottle of formula that has been at room temperature for two hours should be discarded. After this time bacteria can start to grow.
- 4 hours – if stored in a cool bag it should be thrown away after 4 hours.
- 24 hours – formula can be stored in the refrigerator for 24 hours.
Always make sure that you check the manufacturer’s use-by (expiration) date too.
Can Formula be Reheated?
Not always. If your baby has taken half of their bottle, never reheat this formula as this could cause the growth of harmful bacteria.
If you are using a new bottle of formula and it has been stored in the refrigerator then yes you can reheat this cold bottle of milk.
Don’t reheat the formula in the microwave as this can cause hot spots which can scald your baby’s mouth.
- Coffee Shop Option: If you find yourself in a coffee shop and you’ve brought a premade bottle you can ask for a bowl of warm water to warm this thorough. Place your baby’s bottle in the hot water to warm up the formula.
- Using a Warm Tap: Alternatively, if you have access to a warm tap, you can also hold the bottle under running warm water to heat the formula. Turn the bottle slowly to make sure it heats evenly.
Remember that pre-made formula can only be kept at room temperature for 2 hours. If you take a cool bag this can be up to 4 hours.
How to use formula on the go
It’s safest to prepare your baby’s formula right when they need it to make sure it’s fresh and free from bacteria. But if you’re on the go, you can get ready in advance:
- Pack Hot Water: Take a thermos filled with hot water when you leave home. This should keep the water at the desired temperature – (70°C (158°F) for when you’re ready to make up a bottle.
- Formula Powder: Measure out the right amount of formula powder you’ll need into a separate, small container.
- Mixing: When it’s time to feed your baby add the formula powder to the water and shake the bottle well
By doing this, you can ensure the formula is freshly made and at a comfortable temperature for your baby to drink.
Always consult your pediatrician for personalised advice, particularly for premature babies or those with weakened immune systems.
Is it worth getting a bottle warmer?
A baby bottle warmer is not a necessity but more of a convenient option. You can just as easily warm a bottle of formula as mentioned above.
Baby bottle warmers might be helpful for beneficial for night feeds when you want to quickly get the bottle to the ideal temperature. Before using any bottle warmers, it’s important to follow the manufacturer’s instructions to avoid overheating and creating hot spots.
Here’s a round-up of the best bottle warmers for baby milk
Can you use cold water for baby formula?
The short answer is no. The water is recommended to be hot enough (70 degrees) to kill any bacteria that may be present in the formula powder. You should boil the water as advised and leave it to cool for 30 minutes which will bring it to around 70 degrees.
There are some exceptions, however, always check the formula tin and manufacturer’s guidance for further information.
Is it ok to use bottled water for baby formula?
The advice in the UK is to not use bottled water to make up your baby’s bottle as this may contain levels of sodium or sulphate that are too high for your baby and may not be sterile.
If the water supply where you are is unsafe then guidance is that you can use bottled water. You should still boil this water and allow it to cool for 30 minutes maximum.
The bottled water used should be not exceed the below
- Sodium (or ‘Na’) is not higher than 200mg a litre
- Sulphate (or ‘SO’ or ‘SO4’) is not higher than 250mg a litre.
Does ready-to-feed formula need to be warm?
Ready made formula can be served straight from the bottle at room temperature. If your baby prefers you can warm it slightly in a bowl of warm water or under a warm running tap.
So what’s the answer?
The question of what age can babies drink cold formula doesn’t have a one-size-fits-all answer. Babies have their own preferences when it comes to the temperature of their milk; some may prefer it warm, while others are just fine with cold or formula. If you have specific concerns—particularly for premature babies or those with weakened immune systems—consulting your baby’s pediatrician is always the first step.
It’s crucial to check the bottle temperature before each feeding and to discard any unused formula according to the guidelines mentioned earlier. This ensures your baby receives essential nutrients without exposing them to potential health risks.
Generally speaking, giving your baby cold formula is considered safe, as long as it’s prepared and stored correctly. If you notice signs of stomach discomfort, you might consider switching to warmed formula to see if it makes a difference. Your baby’s comfort and well-being will guide you in making the best choice for their nutritional needs.
Hannah is an Expert Registered Dietitian specialising in Vegan Family Nutrition and Cows Milk Protein Allergy.
She is a respected figure in the field of nutrition and a captivating speaker and sought after media spokesperson being featured in esteemed publications including the Sunday Times, Independent and Huffington Post.
- Registered Dietitian
- First Class Degree in Nutrition
- Over 15 years experience working in the field of nutrition
- Respected Media Spokesperson both in the UK & USA; quoted online, TV and in local and international news
- Writer & Researcher, supporting the BDA and PEN Nutrition