Confused about refrigerating formula

Worrywort98 · 2025-04-04T19:38:40+00:00

Hi guys Just what the title says really... can formula be made in advance and kept in the fridge? Online Google searches say yes, up to 24 hrs. Formula package says no, to always make up fresh when needed. Finding night feeds hard so have been having them made up and in the fridge for that 3am blue hour. Just makes it easier but now I'm not sure if I'm doing the right thing. Tia

DoPenguinsHaveHips · 04/04/2025 20:48

We never had any problems with making 24 hours worth of formula and storing it in the fridge, just grab a bottle and warm it up in the bottle warmer or a jug of boiling water when you need it.

AirFryerCrumpet · 04/04/2025 20:53

Best practice/least risk is to make up fresh each time following the instructions on the pack, using water over 70c.

Second best, for when making fresh isn't possible, is to make up following pack instructions with 70c water, cool as quickly as possible and store in the back of the fridge for as least time as possible but no more than 24 hours.

https://www.tommys.org/pregnancy-information/after-birth/feeding-your-baby/formula-feeding

Formula feeding

Formula is manufactured milk that is designed for babies. It can be used as well as, or instead of, breast or chest milk.

https://www.tommys.org/pregnancy-information/after-birth/feeding-your-baby/formula-feeding

BearyNiceEars · 04/04/2025 20:54

I used pre made cartons for overnight feeds. Baby didn’t mind them cold either so was a win-win for me! Some parents are happy to store formula in the fridge and never had any problems. I never felt comfortable to do it.

jolies1 · 04/04/2025 20:57

I used ready made cartons at night (starter bottles when DS was 5/6mo though…) would just take sterilised bottle and a carton to bed with me.

MrsCarson · 04/04/2025 21:29

DoPenguinsHaveHips · 04/04/2025 20:48

We never had any problems with making 24 hours worth of formula and storing it in the fridge, just grab a bottle and warm it up in the bottle warmer or a jug of boiling water when you need it.

That's how we did it too.
I used to carry boiled measured water in a baby bottle to mix up when we were out.
No way I'd have tried to mix up a bottle fresh at 2 am with a screaming baby on one arm.
What about those perfect prep things Aren't they popular?

AirFryerCrumpet · 04/04/2025 22:29

MrsCarson · 04/04/2025 21:29

That's how we did it too.
I used to carry boiled measured water in a baby bottle to mix up when we were out.
No way I'd have tried to mix up a bottle fresh at 2 am with a screaming baby on one arm.
What about those perfect prep things Aren't they popular?

Show quote history

Making formula with 70c water and cooling/storing is safer than making up bottles with cold water.

Trallia · 04/04/2025 22:45

Your choices here are about the balance of risk you're willing to take of an upset tummy, versus a screaming infant waiting for milk.

Formula powder is not sterile, but if stored dry under ambient conditions its hardly a hive of bacterial growth. (If its warm and damp it could be, though!)

Once the powder is hydrated, the bacteria in it will multiply, and could reach levels that are able to cause upset tummies.

If you make up the formula with hot /boiling water then that'll kill most of the bacteria in the powder at the time you make it up. (It also denatures quite a lot of the vitamins, which is why formula manufacturers give different guidance to the world health organisation on how to make up formula). If you then stick that "made with boiling water" formula in the fridge, it'll rapidly get too cold for the remaining bacteria to grow at any rate. It's then probably safe a baby to drink it a few hours later.

If you make up formula powder into warm water and it was stored dry, with low levels of bacteria, and feed it to a baby immediately then there probably isn't time for the bacteria to multiply to a point that is dangerous.

So, safest is to make up fresh with water hot enough to kill bacteria and cool to feeding temperature and feed immediately.

Next safe is to make up with hot water and store in fridge.

Least safe is to make up with warm water and feed immediately.

But most of the time all of them will be fine. What you need to avoid is starting with lots of bacteria present, giving it lots of warmth and water, and then giving loads of time for it to multiply. As an manufacturing engineer who used to work in food doing calculations on how long we could leave things warm and wet before the bacteria levels could be harmful, I did all 3!

Fullcircle90 · 04/04/2025 22:49

Make up bottles as normal with boiling water, let them cool and put them straight into the fridge. They can be kept for 24 hours

CuriousGeorge80 · 04/04/2025 23:45

Two kids in. After each reached three months, we moved from pre made at night to making batches of bottles for a 24 hour period - made into hot water, stored in fridge. Never has a problem at all with either child with this approach.

Original poster

Worrywort98 · 05/04/2025 21:08

Trallia · 04/04/2025 22:45

Your choices here are about the balance of risk you're willing to take of an upset tummy, versus a screaming infant waiting for milk.

Formula powder is not sterile, but if stored dry under ambient conditions its hardly a hive of bacterial growth. (If its warm and damp it could be, though!)

Once the powder is hydrated, the bacteria in it will multiply, and could reach levels that are able to cause upset tummies.

If you make up the formula with hot /boiling water then that'll kill most of the bacteria in the powder at the time you make it up. (It also denatures quite a lot of the vitamins, which is why formula manufacturers give different guidance to the world health organisation on how to make up formula). If you then stick that "made with boiling water" formula in the fridge, it'll rapidly get too cold for the remaining bacteria to grow at any rate. It's then probably safe a baby to drink it a few hours later.

If you make up formula powder into warm water and it was stored dry, with low levels of bacteria, and feed it to a baby immediately then there probably isn't time for the bacteria to multiply to a point that is dangerous.

So, safest is to make up fresh with water hot enough to kill bacteria and cool to feeding temperature and feed immediately.

Next safe is to make up with hot water and store in fridge.

Least safe is to make up with warm water and feed immediately.

But most of the time all of them will be fine. What you need to avoid is starting with lots of bacteria present, giving it lots of warmth and water, and then giving loads of time for it to multiply. As an manufacturing engineer who used to work in food doing calculations on how long we could leave things warm and wet before the bacteria levels could be harmful, I did all 3!

This is very helpful! Thank you so much to you and everyone who has responded x

OP posts:

Sofiewoo · 05/04/2025 21:09

It’s safer than a perfect prep and they store formula in the fridge in UK hospitals so the risk can’t be that high.

AliBaliBee1234 · 05/04/2025 21:12

I was told it's a no from an nhs feeding advisor unless you have no other option.

I used a nuby rapid cool and flask which sped up the process

Trallia · 05/04/2025 22:13

Going to re-emphasise the risk element here. When I had a premie newborn, I always made my formula up with boiling water (though did then keep it in the fridge overnight).

By the time I was making it up with power and warm water and feeding immediately (I.e. no equalvalent step to pasteurisation) she was crawling around the garden grabbing handfuls of grass and trying to stuff it in her mouth.

Never make up formula without warm water and keep it for any length of time undrunk. Bacteria will be multiplying exponentially...

And if you anyone reading this doesn't understand enough of what I've written to appreciate the risks, then stick to what the manufacturers or WHO/NHS advise: it is the safest option. Just not the one that minimises disruption to sleep and hungry baby wah.

Those rapid cool devices are amazing, bit I didn't have one!

I'm not fond of perfect prep machines- they're okay if you clean and maintain them - but busy sleep deprived parents often don't! And then there's this: <a class="break-all" href="https://www.google.com/url?q=www.bbc.com/news/uk-wales-67001503" rel="nofollow" target="_blank">https://www.google.com/amp/s/www.bbc.co.uk/news/uk-wales-67001503.amp
If they dont get up to temperature, it's the same as making your formula with warm water and feeding it immediately.

Maxorias · 05/04/2025 22:28

I'm confused why people think it's easier to make the formula in advance and store in fridge, rather than just have a thermos of hot water, empty bottle and pre-measured formula powder on the side of the bed. Then you don't even have to get out of bed. And it's faster.
(if people absolutely want to kill bacteria you can make the formula with half boiling hot water and half cold water).

QueefQueen80s · 06/04/2025 09:15

Yes I always make enough for the next 24 hrs, make with boiling water, put in fridge and then gently warm with bottle warmer when needed. Takes a few mins when baby is crying

I started off making them fresh every time as per the formula instructions, baby was not happy waiting half an hr for it to cool down!

Emmacb82 · 06/04/2025 09:19

I would make them fresh but I always had a bottle of cool boiled water ready to go. I would add some boiling water to the bottle and add the powder to kill the bacteria and then top up with the cool boiled and it’s ready to go straight away.