What do I need to do first?

Before you sterilise, you’ll need to carefully clean and rinse the used bottles from any residues of milk or formula with a cleaning agent like Pigeon’s Liquid Cleanser.
You can also use a dishwasher to wash your baby’s bottles. You may want to wash the teats separately though, to be sure they’re totally clean. Check teats and bottles carefully and throw out any which are badly scratched, split or cracked. Bacteria can stay in damaged surfaces and survive the cleaning and sterilising process.