Do I need to boil water to make formula milk to feed my baby?

Yes. You should always boil water before using it to make up formula milk using powdered baby formula. Boiling the water will kill any bacteria in the water that may make your baby ill.

Before using it to make a feed, let the boiled water cool in the kettle for about 30 minutes so that it’s lukewarm, or about body temperature.

To make your baby's feed, put the water in the bottle first, while it’s still warm. Then add the powdered formula and mix well.

If the formula milk is too warm, hold the bottle, with the cap covering the teat, under cold running water to cool it. Give the bottle a shake to get an even temperature throughout the milk.

To save time, you could pour the correct amount of boiling water into several bottles, place the lids on tightly and store the bottles in the fridge. When you need to make a feed, remove one of the bottles of cooled, boiled water, add the correct amount of formula, shake and warm the bottle to your baby’s preferred temperature, if necessary.

Warm the bottle by standing it in a bowl or jug of warm water, for 15 minutes or less, or in a bottle warmer. Shake the bottle gently to get an even temperature.

Or you could work out how much freshly boiled water to add to your cooled, boiled water to get the right amount of water at your baby’s preferred temperature. For example, you might need to add 45ml of boiling water to 55ml of cooled water in your bottle from the fridge to get 100ml of water at the perfect temperature.

Before you give your baby a bottle, test the temperature of the feed by dropping a little on to the inside of your wrist. It should feel warm, not hot.

Don't use artificially softened water or water that’s been boiled before. If you have to use bottled water, you’ll still need to boil it.

Make up a fresh bottle for each feed. It's best to throw away untouched and unfinished formula milk within one hour. Bacteria can multiply rapidly in formula milk kept at room temperature, and can still multiply slowly in the fridge.

Occasionally, though, you may just have to make up a bottle in advance. Find out how store formula milk safely.