Shelf life and Validation of Coconut Milk?
Refrigerated coconut-based milk substitutes like Silk Pure Coconut or So Delicious Coconut Milk have a stated lifespan of 7-10 days after opening.  I've had cartons last longer than that without any change in taste or smell, but if it started tasting bad or smelling funky I would toss it.  Unfortunately, this type of coconut milk product does not reconstitute well after freezing.