"To sterilise the bottles" means to clean or disinfect the bottles thoroughly to kill any bacteria, germs, or microorganisms that may be present in order to make them safe for use. Full definition
The television sample included only one reference to potential bottle feeding difficulties (the time consuming practice of sterilising bottles, Liverpool Mums, Channel 5, 15 March). (bmj.com)
Carla's Honest Review on The Tommee Tippee Closer to Nature Electric Steam Sterliser People used to tell me how difficult and time consuming sterilising bottles could be, then a friend of mine introduced me to her Tommee Tippee Closer to Nature Electric Steam Sterliser. (mybump2baby.com)