Here is what I did for 22mths of EPing. Those storage guidelines are the BEST online, they come with temperature ranges not just how many hours you can leave it out for because it is different it your house is 60degrees or 80degrees.
Frozen milk is a bit tricker.... I always kept the bottles small since my DD was a snacker especially after she got older, NEVER more than 4oz mostly 2-3 unless it was nap time and then I knew she would surly finish the 4oz plus some since she LOVED to suck

. If I had extra and i knew that she would not finish it in the next hr or so I would put it back in the fridge. I would not pull it out for the next feeding unless it was a substantial amount, say over 1oz. If less than that I would start a new bottle of frozen and follow the same pattern, putting the extra back in the fridge if it was not finished after an hr or so. This pattern would go on all day. By the end I would have a few bottle left that had less than 1oz in them accumulated in the fridge, I would pour them all into one bottle and that would be her first bed time bottle. I always knew she would finish it so the milk never went to waste and was never mixed with new milk. the second bed time bottle would be heated and then if she fell asleep before finishing it I would put it back in the fridge and give it to her in the AM when she woke. I would avoid heating milk at night and only used fresh then since it took so long to get it warm (I did not want her to have to wait) and I hated going down to the kitchen half asleep

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I know most of you nurse to sleep and bottles are just a daycare thing but you could do something similar with storing the small extras in the fridge and then using them all at once at some point at the last feeding of the day. Then if the nanny has to start a fresh bottle of frozen milk after the first bottle that was the mixture of the small leftovers that second bottle can just be put in her fridge and used as the beginning of the first feeding the next day. If your babe is not going to daycare the next day you can bring it home and give it there if you really don't want to waste it but I would not store it for more than 24hrs after being frozen, heated once, drank from, left out for about 1hr and then refrigerated. That just seems like a lot to me.

Happy pumping
