Sterilising bottles in the oven lets you prepare them ahead of time and avoids the risk of tasting sanitiser

Remove any caps if present, as these will be damaged by the oven

Clean all bottles with soap and a bottle brush, then rinse thoroughly to ensure no soap residue remains

Stack the clean bottles in the oven, turn to a low heat and set a timer for 15mins to fully dry them out

At 100C/212F turn off the oven, but leave the door closed until the bottles are cool or they may break

While the bottles are cooling, cut some silver foil into 10cm/4in squares, one for each bottle

When the bottles are cool and dry, place a piece of foil over each one - this will keep them sterile

Restack the bottles in the oven

Turn the oven on low and set a timer for 15mins - the bottles need to be heated gradually to avoid breaking

After 15mins increase the temperature a little and set another timer

Check the temperature again after 15mins and increase again, set another timer

After 15mins increase the temperature again and set another timer

When the temperature is 170C/338F set a timer for one hour - this will sterilise the bottles

After one hour turn off the oven, BUT DON'T OPEN THE DOOR - allow to cool closed which will take 1-2 hours

When the oven is cool, remove the bottles and write an S on the foil so you know which ones are sterilised