How Long Is Formula Good For, and How Should I Store It?
How long your formula will be good for depends on whether it’s been opened and how it’s stored.
An unopened box will stay good until its expiration date. This might be anything from a few months to a year after you bought it – it’s always worth checking if you don’t use much formula (we deliver all powdered formula with an expiration date at least 6 months ahead unless otherwise stated).
Once you’ve opened the box, you should use it within two weeks to guarantee freshness – but you’ll need to make sure it’s stored safely and carefully.
How to store an open box of formula
Many parents automatically store their formula on the kitchen counter or in a cabinet above – usually the same place you keep your bottles, pacifiers and sterilizer. This is the convenient option, but it’s not always the safest.
Kitchen counters and cabinets can be damp and warm (especially if they’re near a sink, hob or sunny window), and that’s not good for formula. Make sure you choose a cool, dry place away from kitchen appliances.
The one place you should never keep formula is in the refrigerator or freezer. This might sound like it would extend the life of your formula, but the humidity inside will get into the box and cause the powder to form clumps. This means you’re likely to end up making your bottles up with too much formula vs water, which can make your baby dehydrated and even cause kidney damage.
Wherever you store it, you have more than one box, it’s a good idea to store the one with the earliest expiration date at the front – many parents have ended up wasting formula by storing the oldest box furthest away!
How long can you store made-up formula?
Once you’ve made up bottles from powder formula, they’ll keep for 1-2 hours at room temperature, or 24 hours in the refrigerator. This means that you’re going to be out over a feed time, it’s easiest and safest to take ready-to-feed formula with you.
Many parents make up all the bottles they’ll need for the day each morning, and refrigerate them until they’re needed. This is totally safe, but you should keep them right at the back of the refrigerator, where the temperature is at its coldest. Never keep made-up bottles in the door, as the temperature will fluctuate every time you open it.
You could also make up a pitcher of formula, refrigerate it and pour out the amount you need into a bottle at each feed. Again, this is totally safe as long as your pitcher is kept as clean as your bottles.
Some babies will drink cold formula, but most will prefer it warmed to somewhere around 98℉ – the same temperature as breastmilk. It’s easy to do this with an electric bottle warmer or a bowl of hot water (but never use a microwave, as this causes dangerous hot spots in the milk).
And you should never freeze formula. This breaks up the milk and causes the fat to separate. Even shaking and warming it won’t turn it back into drinkable formula – you’ll need to throw it away.