Confused about bottle sterilising?

[PregnantPossum]

Parents to a newborn and very confused about bottle sterilising.

We are currently using the microwave bags to sterilise bottle parts and trying to do a few in one go. We have ordered a steam steriliser machine which we’ll start using soon.

However I have read that as soon as you open the bag or steriliser machine, the contents are no longer sterile.

Does this mean that realistically you have to sterilise only what you need / one bottle at a time and can’t sterilise other bottles in advance for use later in the day? Or in practice do people just ignore this and pre-sterilise multiple bottles?

I kept my clean bottles and parts in the steriliser and just lifted out what I needed. Once a bottle is used wash it and leave it to the side and when you have enough stick the steriliser on again.

I put the steriliser on once in the morning and once at night. It was the Tommee Tippee steam once and held 6 bottles but my DS fed every 3 hours so we needed 8 a day.

I ignored it, sterilised once a day and touched them as I used them and assumed they stayed reasonably sterilised until I used them.

You sterilise them all in one go and then with clean hands assemble them so the bottles are closed. Then use as needed.

The bottles have to be sterilised from the bacteria that grows in them because of the milk, not the air around you. Your baby will be sucking on their hands and shoving all sorts of things in their mouths. The world doesn’t need to be sterile, just the bacteria that can grow in milk.

They're sterile for 24 h, at long as you don't touch the inside surfaces or any part that will contact your baby's mouth. They're perfect safe in the steriliser for 24h after cleaning.

Sterilise and then assemble the bottles and use within 24 hours