For the past year I haven't been able to keep milk in my fridge for more than 4-5 days. I always buy the freshest milk, not expiring for a couple weeks from purchase. However, the milk sours in my fridge in 4-5 days no matter what brand or size of milk. After 4-5 days the top of the milk is filmy and smelly. Even more drastic I bought two 12oz bottles of milk yesterday. I drank one last night and it was fine, but I went to drink the second this morning and it was rank, I poured it down the drain and it was chunky. My fridge cold level is 7 out of 10. 10 being coldest. I have no problem keeping any other foods for a long time and everything feels cold to the touch. Anyone have ideas why I can't keep milk for long, it's sooooo annoying!