Once you thaw and warm the EBM, DO NOT RE-FREEZE. It will cause bacteria to grow in the milk. If baby didn’t finish, leave in the fridge and consume within 2 hours.
Moving forward, pack your EBM in bags of 60ml. If ever the unfinished milk has passed the expected time, don’t throw it away. Use it as milk bath for baby. Good for their heat rash, diaper rash, etc.
https://www.cdc.gov/breastfeeding/recommendations/handling_breastmilk.htm