Feeding a baby formula milk at night is a massive faff compared to breastfeeding. Having to make up a bottle to the correct temperature and following all the guidelines is so much harder than just getting your boob out. The only advantage is that it can be shared with a partner.
If you could just have some prepared bottles kept next to your bed it would be fine. But bacteria love milk as much as babies do. And babies have very underdeveloped immune systems so could become unwell with sickness or diarrhoea or even become seriously ill from drinking contaminated milk.
So what are the best ways to make up your baby’s bottle safely at night? Here are your options along with a rating of how much effort they are (with five being the most effort required).
OPTION ONE: the NHS recommended method
Effort rating: 5/5 (a lot of effort)
The NHS advise that bottles of formula are made up fresh for every feed. And when they say fresh, they mean that it has to be done like this:
Boil at least one litre of fresh tap water in a kettle and once boiled use it within 30 minutes. This is because the water has to be at least 70°C to kill any possible bacteria in the formula powder, which is not a sterile product. Boiled water will stay at more than 70°C for half an hour.
Pour the boiled water into a previously sterilised bottle.
Add the correct amount of formula powder and shake.
Cool the bottle down to body temperature. To check this shake a few drops of milk on the inside of your wrist. It should feel warm or cool, not hot.
Ways you can cool a bottle of milk down
A bottle made with freshly boiled water is obviously way too hot for a baby to drink. But with a baby crying in the night you don’t have time to wait for it to cool down naturally. So here are your options:
Keep a big mug, jug or bowl of iced water in the fridge and place the bottle of milk in it. Cooling time for a 150ml bottle is roughly 8 minutes.
Place the bottle under a tap of cold running water. Cooling time for a 150ml bottle is roughly 8-10 minutes. Although it feels like ten years as you have to stand there holding it.
Use a Nuby RapidCool™. This award-winning gadget will cool milk to the correct temperature. You make up the formula feed as normal but inside the RapidCool™ not a bottle. It will then cool it down. Cooling time for a 150ml bottle is 3 minutes. It is quiet and portable and so can easily be kept in the bedroom. The downsides are that it has to be cleaned and sterilised after each use, which would be annoying if your baby had more than one night feed. It also may not fit in your steam, UV or electric steriliser so would have to be cold water sterilised. And because it absorbs heat it has to have a cooling off period between uses. Depending on your sterilisation method, this is 3-4 hours.
One way around all this is to buy the RapidCool kit. This comprises two RapidCool bottles plus an insulated flask and two milk powder dispensers.
Tommee Tippee brought out a rival to the Nuby RapidCool in 2023 called the GoPrep. There’s virtually no difference between the two so which one you get will be down to personal preference and price.
OPTION TWO: the flask method
Effort rating: 4/5 (quite a lot of effort)
This is the method that the NHS recommend for formula feeding when you are out and about for the day. They don’t specifically recommend it for regular night feeds.
It’s very similar to option one but cuts out the kettle bit. Instead, you fill up a flask with just boiled water before you go to bed. A good flask that is full and pre-warmed will stay at 70˚C or above for several hours.
The Esbit flask is great as the 500ml one can keep water above 70°C for six hours and the 1000ml flask can keep it above 70˚C for 12 hours. It also has a push-button lid so can be used one-handed. I had the 500ml one and loved it. I still use it now even though my baby feeding days are over as it’s amazing at keeping water hot for ages.
The Flintronic insulated bottle has an LED temperature display so you know if the water is hot enough. It can keep water above 70˚C for up to six hours.
If you want to prepare the feed from the warmth of your bed, keep the flask on your bedside table along with sterilised bottles and powdered milk dispensers. When you need the milk, pour the water from the flask into the bottle and then add the formula powder. You now have a freshly prepared bottle in line with NHS guidelines. (Obviously, keep your baby well away from boiled water.)
There are also baby kettles that keep water at a certain specified temperature. For example, the ÜneeQbaby kettle, which maintains water at 37˚C-70˚C for 24 hours and at 71˚C - 90˚C for three hours.
These claim to make life easier as they have the option to maintain body temperature water and therefore make ready-to-drink formula. But the NHS and WHO state that the water mixed with formula powder should be a minimum of 70˚C in order to kill any bacteria.
You should also check that the kettle isn’t keeping the water hot by repeated reboiling. Water for baby bottles should be fresh each time the kettle is boiled as reboiling it increases the level of sodium in the water and could harm the baby’s immature kidneys.
The only problem with the flask or baby kettle method is cooling the milk down once the boiled water has been mixed in. See above for the best ways to do this. Unfortunately, they all involve waiting for a good few minutes, which can feel like a lifetime with a screaming, hungry baby. It’s a lot easier if you’re combination feeding as you can breastfeed while waiting for the milk to cool down and you could keep a mug or jug or iced water next to the flask so you don’t have to get out of bed.
OPTION THREE: the hot and cold water method
Effort rating: 3/5 (not too much effort)
This is not something that the NHS recommends but many parents do use this method.
You need two bottles and a just boiled kettle or a pre-filled flask. In one bottle add boiling water that is a quarter of the amount you need. For example, if you are preparing a 200ml feed, measure out 50ml of boiled water into the first bottle. In the other bottle, add water that has been previously boiled and then cooled. Measure out three-quarters the amount of water you need. So for a 200ml feed - 150ml.
Next, add the formula powder to the freshly boiled water bottle and shake. Then add the cooled boiled water and shake again. This will give you a freshly made bottle at the right temperature.
It’s important to add the powder to the boiled water immediately as the low volume means it reduces in temperature more rapidly than a full bottle of boiled water.
Like option two, you could keep the bottles, flask, cooled boiled water and powdered formula pot by your bed to make it even easier.
The cold water should be cooled boiled water up until your baby is six months old. After that, the NHS say they can have water straight from the tap.
OPTION FOUR: the baby bottle making machine method
Effort rating: 2/5 (pretty easy)
Baby bottle makers are often used by parents to quickly make bottles of formula. In the UK, the Tommee Tippee Perfect Prep is the most popular and recreates the hot and cold water method of option three.
It makes a bottle to the perfect feeding temperature in two minutes. A small amount of boiling water is dispensed into a bottle which you then immediately add the formula powder and shake to dissolve. The machine will then dispense the remaining amount of water. This water is cold but has gone through a special antibacterial filter that eliminates any impurities from the water.
The Day and Night Perfect Prep has a volume control so it can be used silently at night and it also has a soft night light.
It’s pretty straightforward. You just have to make sure the water tank is full and you have the sterilised bottles and formula powder ready. However, it does need to be put through a cleaning cycle every 4 weeks and every time the filter is changed. They recommend you install a new filter for every 150 litres of formula made. This will be around every three months if you’re doing 6 x 260ml feeds a day. It’s important to use the correct filter and these cost around £12. The machine will also need occasional descaling. So it might be very easy in the night but there will be a bit of daytime faffing involved.
It’s also worth noting that the smallest size feed it can make is 4oz (150ml) and a newborn or combination-fed baby will not drink this much milk in one feed so there is wastage. Formula milk that has been partly drunk should be thrown away after one hour. This is because bacteria can transfer from the baby’s mouth and grow rapidly in the milk.
The Tommee Tippee Perfect Prep is extremely popular but it is not without its critics. The company that makes them has tested the machine in an independent laboratory and is satisfied that the initial hot shot of water kills any bacteria in the powder. But in 2014 the Food Standards Agency expressed some concerns. You can read more about this here.
There have also been reports of black mould being found in the pipes of a Perfect Prep but Tommee Tippee have stated that if you use the correct filter, which is changed regularly and you carry out regular cleaning cycles there should be no issue. If you are still worried, they have said you could run an extra cleaning cycle before the recommended one using a sterilising solution such as Milton or food-grade white vinegar.
You can read reviews and buy the Perfect Prep here:
For a comparison of the five most popular baby bottle makers, see here.
OPTION FIVE: the pre-prepared bottle method
Effort rating: 1/5 (easy)
We all know by now that freshly made is best but many parents prepare them in advance. This method is described on the NHS website as the second-best alternative to the flask method if you need to feed when away from the home or transport a feed. They do not specifically recommend it for regular night feeds.
The safest way to pre-prepare bottles is to make the bottles in the evening in the normal way, ensuring the powder is added to freshly boiled water. Then immediately cool the milk under running cold water or in a bowl of cold water. Next place at the back of the fridge (not in the door shelves) where they will stay fresh for 24 hours. You could also put them in a cool bag with an ice pack, where a bottle will stay fresh for 4 hours.
Then, when required, take one out and either give it to your baby cold or warm it up using a bottle warmer or by placing for a short while in a mug/jug/bowl of hot water.
Don’t use a microwave to warm up formula milk. It does not heat the milk evenly and could create hot spots that may burn your baby’s mouth.
Can babies drink refrigerator cold formula?
Yes, it’s fine. Although it has been suggested that for very small newborns or premature babies it is best to warm it up as this means they aren’t expending energy to regulate their overall temperature.
It has been also suggested that warm milk is easier for babies to digest but there hasn’t been any firm evidence to prove this.
You may find that your baby will prefer their milk warmed as breast milk is (unsurprisingly) body temperature.
OPTION SIX: the ready-to-drink formula method
Effort rating: 0/5 (very easy)
Most formula brands also sell a ready-to-drink version. This is a ready-made liquid formula that comes in bottles and is completely safe to use. As long as they are unopened they can be kept at room temperature which most babies will be happy with. So you would just need to grab a bottle of the liquid formula and pour it into a sterilised bottle and you could keep both by the side of your bed. If they want it warmed up slightly you could use a bottle warmer or put the bottle in a mug of boiled water (well out of reach of your child). Keeping boiled water in a good flask will mean you are not also having to wait for the kettle to boil.
One downside is that they are more expensive than powdered formula and are often around double the price. You might not be happy about the environmental cost of all the small plastic bottles it comes in. And another drawback is that they usually come in bottles of 200ml. Most babies won’t drink as much as 200ml in one feed until they are around four months or older. The remainder can then go back in the fridge but has to be used within 24 hours. And then, unless your baby is happy with cold milk, you will need to warm it.
Conclusion
Night feeds are hard and making fresh bottles with freshly boiled water every few hours makes it even harder. But this is the safest option unless you are able to use the more expensive ready-to-drink formula. Despite this, many parents use one of the other options without any problems. I hope all this information will help you make an informed decision about your nighttime formula feeds. What do you think? Which option above do you prefer?
If you buy through a link on this site, I may earn a small affiliate commission. 5% of profits will be donated to UK Baby Banks to help parents in need of essentials.
ABOUT THE AUTHOR
Annabel Port is the founder of Get Get Got and in a former life, a Sony award-winning radio presenter. After the birth of her son, she brought her forensic research skills to the world of baby products to help new parents not repeat her mistakes.
DISCLAIMER: I am not a health professional and everything provided here is for informational purposes only and is no substitute for advice from your health visitor or GP. Where I have stated that other parents use a particular method, it does not necessarily mean that it is safe for your baby or that I endorse it. Following of any of these methods is entirely at your own risk.
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