We have the TT microwave steriliser and the instructions are so vague I'm not sure if I'm doing the right thing If you sterilise a batch providing the lid is left on are they sterile for up to 24 hours? If you take one out and replace the lid does this make them not sterile? Can you sterilise a batch , assemble the bottles and take them out and they will still be sterile ? Are you best to sterilise each bottle again before a feed? Everywhere is conflicting and I'm scared I'm doing the wrong thing !!