I think the temp should pay the most impt.part. you can go to singapore health promotion board webbie to get the recommended storage time for frozen breast milk. If i not wrong is 3-6month. Kandang Kerbau Hospital's bf booklet says keep at -15degrees is about 3-6months too. If you worry that the temp.in the.fridge.keeps changing bcoz.you.open and close.it.often, get a thermometer and put.inside the.fridge to.monitor the temp. Diaso have them. Cheap and good.