Infant formula storage guide

If you choose to formula-feed your baby, it’s important to understand the ins and outs of formula milk storage. If it’s not stored properly, milk can be an ideal environment for bacteria to thrive, which can make your baby poorly¹.

Storing formula milk properly (and sterilising your feeding equipment) prevents bacteria from growing and helps keep your baby safe and healthy.

Our guide to storing infant formula  answers frequently asked questions like ‘can you put formula in the fridge?’ and ‘how long does formula last once opened?’

Read on to find out everything you need to know about formula milk storage.

Store unopened tubs of infant formula in a cool, dry place, such as your kitchen cupboard. Once opened, keep powdered formula in the cupboard (not in the fridge) with the lid tightly shut.

Check the instructions on the packaging to see how long your powdered formula lasts once opened, and make sure to throw away any remaining formula after that time has passed (and after the expiration date).

To use powdered formula, mix the right amount of powder with boiled water that has cooled down water in a feeding bottle according to the manufacturer’s instructions and steps.

The safest way to use formula is to prepare a fresh bottle every time you need one and give it to your baby as soon as it reaches the right temperature. If your baby doesn’t finish the whole bottle within 2 hours, you should throw away the leftover milk².

Ideally, you should make a fresh feed every time your baby needs one. But if you do make a bottle in advance and store the formula in the fridge, you should make sure the temperature is 5°C or less and throw away unused formula within 24 hours¹.

Never use a microwave to warm formula milk from the fridge, as they heat unevenly and may lead to hot spots in the milk that could scald your baby’s mouth¹.

Instead, you can follow these steps¹:

1. Remove the formula milk from the fridge just before you need it.
2. Place the bottle upright in a bowl of warm water, keeping the neck of the bottle above the water level.
3. Check the temperature by dripping a little milk onto the inside of your wrist. It should feel lukewarm, not hot.
4. Throw away any formula milk that your baby hasn’t finished after 2 hours.

Avoid reheating the formula milk more than once.

The best way to formula-feed your baby away from home is to make a bottle on the go. You’ll need to take²:

• A clean, dry container containing a measured amount of formula powder
• An empty, sterilised feeding bottle with its cap and ring in place
• A flask of just-boiled water (only if you don’t have access to a kettle)

You can use the powder, hot water and empty bottle to make up a feed according to the manufacturer’s instructions when you need it. Just remember to cool the bottle under running water before feeding your baby².

If you’re unable to follow the advice above, you can use ready-to-drink liquid formula. Make sure your hands are clean, then just shake the bottle  and pour the amount you need into a sterilised feeding bottle.

Ready-to-drink formula comes in a bottle or carton in liquid form. You don’t need to do anything to prepare it except shake it and pour it into a sterilised bottle, following the manufacturer’s instructions.

Store unopened bottles or cartons of ready-to-drink formula milk in a cool, dry place such as your kitchen cupboard. After opening, you should refrigerate any leftover milk still in the bottle or carton immediately at the back of the fridge on the top shelf for no longer than 24 hours.

Any milk that has been in a bottle that you’ve given to your baby should be thrown away within 2 hours.

You can keep any ready-to-drink formula milk left in its original container in the fridge for up to 24 hours.