How Long is Formula Good For?

Juggling all things baby can be tricky.

So to save time, you might want to prepare baby's formula in advance.

But how long is formula good for, and how do you store it?

Babies only want to eat, sleep, and be cuddled.

Seems like an easy list, right?

But things can get confusing when you’re getting to grips with formula feeding your little one, especially as you’re probably feeling (to put it mildly) quite tired.

Nourished is best, so let's take a look at how to prepare a bottle, how long formula is good for, and how to store formula safely.

In this article: 📝

First things first – how to make up a bottle

1. Wash your hands with soap and water.
2. Make sure the bottle, rubber top, and lid are all sterilized in a microwave steamer, boiling water, or sanitizing solution. [1]
3. Measure cooled boiled water into the bottle and then add formula powder. Doing it in this order makes sure you keep the right ratio of formula to water.
4. Tighten the lid and shake the bottle to mix. When all the lumps have dissolved, test the temperature of the formula on your wrist. It should be at body temperature or just below.

But what happens when your baby’s finished chowing down?

Is it safe to keep the formula you made for later?

How long does formula last?

Short answer: it depends.

There are a few things to consider here ‒ when the formula was made, how long ago it was heated, and how it’s been stored.

So let’s break it down.

How long is formula good for once mixed?

How long is a formula bottle good for?

Once you’ve prepared a bottle, the milk lasts for about 2 hours at room temperature.

But once your baby drinks some, you’ve got a maximum of 1 hour before you should pour it away.

If you’re in a pinch and don’t have much time to prepare your babe’s formula, you can try the Perfect Prep machine by Tommee Tippee.

Fill the tank with water, choose your feed size (from 4 fl oz to 11 fl oz), add your formula powder, pop your bottle in the stand, press the power button, which will fire out a ‘hot-shot’ of water to kill any bacteria in the bottle and dissolve the powder.

Put a leak-proof lid on the bottle, give it a good shake, then put it back in the stand for the cooler water.

In under 2 minutes, it’s ready ‒ at the perfect temperature for your babe.

Quick and easy!

Why is formula only good for an hour?

If your baby started a bottle and dozed off before they had a chance to finish, you might even want to pour the leftovers away immediately.

This guideline exists because formula milk is warm, sweet, and full of nutrients, which makes it the perfect environment for bacteria to grow.

If your baby comes back to drink an old bottle after more than an hour, there’s a chance they could get sick.

Our top tip: get your hands on a portable formula feed maker, like the GoPrep by Tommee Tippee, so you don’t have to fret about whether the formula is fresh and warm enough for your babe if you’re out and about.

All you need to do is add boiling water and formula powder into the cool flask, tighten the lid, give it a good shake for about 2 minutes, and the colour-coded star will tell you when it’s at the perfect temperature.

Then transfer to a sterile bottle, and baby’s ready to feed!

How long can formula stay in the fridge?

Refrigerating formula so it’s ready to warm up and go can make parent life a lot easier.

It’s best to keep the bottles in the back of the refrigerator, where the temperature is lower and more constant than it is in the door.

Once you’ve made the bottle up, you can keep it in the refrigerator for 24 hours.

Again, once your baby has drunk from the bottle, you should get rid of any remaining milk within the hour.

Ready-to-feed formula storage

Ready-to-feed formula is more expensive than powdered but the chance to skip the boiling, cooling, and mixing stage of bottle prep is very convenient.

Ready-to-feed formula can be stored in the pantry at room temperature until you’re ready to use it.

You can keep an open container in the refrigerator for 48 hours, as long as your baby hasn’t drunk from it directly.

How long does a container of formula last?

How quickly your family goes through a container of formula depends on how hungry your little peanut is.

A family that’s mixed feeding might only need one container a month, but a baby drinking six 8oz bottles every day will get through that in no time.

Does powdered formula go bad?

As for how long the formula lasts until it goes bad, most containers of powdered formula recommend using them within one month of opening, regardless of how much is left.

If you keep it for longer, moisture can affect the texture of the formula and there’s a higher chance of bacteria starting to grow in the container.

Can you freeze powdered formula?

Although it’s possible to freeze expressed breast milk, formula doesn’t belong in the freezer either in powdered or liquid form.

The powder won’t mix well with water once it’s been frozen, and thawed liquid formula usually separates.

It’s safer, not to mention much more appetizing for your baby, to mix it on the day you need it.

So formula can keep for a little while, but if you can make it fresh, baby’s more likely to prefer the taste.

If you’re ever in doubt about whether your prepared formula is still okay for baby, it’s worth checking with your doctor or asking the Peanut Community for advice.

You’ve got this.