Recommendation is to store breastmilk at 4 degrees celcius for 48hours only be it whether is it a dedicated fridge. Anything after 48hours have to be discarded. Anyway the longer you store your breastmilk, the more nutrients will be gone, be it you freeze it or refrigerate it. You may refer to this guidelines for more information - https://www.healthhub.sg/live-healthy/1141/pregnancy-feeding-your-baby-breastfeeding