Freeze It Flat Breastmilk Freezer Storage System - Space-Saving Organizer for Breast Milk Storage Bags - Freezer Organization Made in USA (Black, Single 1-pk)

I personally use these freeze flats they work so well but they’re expensive! cheaper option would be to use plastic pencil cases and stack the bags on top to force them to freeze flat. Then as the other commenter mentioned, put them into “bricks”. If you have a costco membership, kirkland gallon freeze bags are larger than regular ziploc. I can put up to 19 bags of 5oz, for a total of 95oz per “brick”. I had a similar huge oversupply so I caved in and bought a dedicated freezer for my bm. I got a secondhand 11 cu ft freezer for cheap on fb marketplace and it’s still not full after I’ve been putting away milk from february-now! Once I run out of space i’ll look into donating atp