Making Formula - A Checklist

Making Formula - A Checklist

A checklist for making and warming baby's formula safely.


Read the formula labels carefully (including the use-by date) and follow instructions.

Formula is best made up fresh in time for each feed. 

Step 1

Clean and disinfect a surface for preparing the feed.

Step 2

Before you handle sterilised equipment or make formula, thoroughly wash your hands with soap and water and dry them on a clean cloth or paper towel.

Step 3

For the first 6 months, boil and cool all water used for formula on the day you use it.

If you are using a jug or kettle to boil water, wait until it switches off. If you are boiling water in a pot on the stove, let the water come to a rolling boil. Once the water is boiled, leave it to cool, then pour into a sterilised container, cover and put into the fridge. This is your supply of cooled, boiled water to use for the whole day. Keep only for 24 hours.

Step 4

When your baby needs a feed, pour the correct amount of cooled, boiled water into the sterilised feeding bottle before adding the powder.

Not all baby bottles have accurate volume lines on them. To check that your bottles do, look for the standard mark EN14350 on the bottle or packaging. Or, take your bottles to a pharmacy and ask a staff member to check if the bottles are accurate.

Step 5

Use the scoop and instructions provided with each tin to measure the formula powder. Level the powder with a clean knife, but don't pack down the formula. Add the correct number of full, level scoops of powder to the measured water in the clean, sterilised bottle.

Step 6

Attach the teat and collar to the bottle. Seal the bottle with the cap. Shake or swirl the bottle gently until the formula is mixed thoroughly.

Step 7

Handle and store the prepared formula with care. Infant formula powder is not sterile. The temperature at which babies like their formula is also a perfect temperature for harmful bacteria to grow.


  • never add more formula powder or less water than recommended - this could make your baby very sick
  • never add anything other than formula powder or water into the formula feed

In cities and towns, you can use water straight from the tap to make formula after your baby is 6 months old. Run the tap for 10 to 15 seconds before you collect the water. 

You need to boil bore water and tank water until your baby is 18 months old. If you have a bore, check with your local public health unit that your water is low in nitrate. If the nitrate level is high, ask your public health unit for advice.

Make formula just before use. If this is not possible, prepared formula may be stored:

  • at room temperature for no more than 2 hours
  • in the bottom half of the fridge at the back (2 to 4°C) for no more than 24 hours

Warming formula

You can warm formula to body temperature for your baby, but never reheat warmed or partly used feeds. Always check the temperature of the formula by shaking the bottle and dripping some of the formula on the inside of your wrist (without touching the teat). Formula that feels just warm on your wrist is safe for your baby.

Formula that is too hot or unevenly heated can cause serious burns to the baby's mouth and throat.

With any warming method, make up the formula just before warming. When the formula has been warmed, use it within 2 hours and throw out any unused formula.

Options for warming

Hot water bath. Place the bottle of prepared formula in a container of hot water. Before you feed your baby, shake the bottle thoroughly so that the formula is at the same temperature throughout the bottle. Check the formula’s temperature.

Baby bottle warmers. Most of these devices are electric and warm the formula to a safe temperature within a few minutes. Follow the manufacturer’s instructions for use. Choose a bottle warmer that sounds an alarm when the safe temperature is reached and then automatically switches off. Always shake the bottle once it is warmed and check the formula’s temperature before giving it to your baby.

Some baby bottle warmers use other ways to heat the formula, for example, using a car battery or activating a metal disc in a reusable warmer pouch. Both of these products are safe to use as long as the formula is prepared by mixing the water and powder together just before warming. Once the formula is warm, remove the bottle from the warmer, check the temperature and finish feeding your baby within two hours. Throw away any unused formula.

It's best not to use microwaves for warming formula because they can overheat the formula or heat it unevenly and burn your baby's mouth and throat. If you do need to use a microwave, follow these steps:

  • halfway through the heating process, stop the microwave, remove the bottle and shake it thoroughly
  • continue the heating process
  • after heating, let the bottle stand for 2 to 3 minutes
  • shake the bottle again and check the formula’s temperature before giving it to your baby

Never reheat warmed or used feeds.

Watch the video and find out how to make baby's formula

This page last reviewed 21 November 2022.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it