There's probably a real, scientific explanation for how long it can go, dealing with
pasteurization and
homogenization and all those other -ations. But truly, it just comes down to how
adventurous you are. The
expiration date is very much a
psychological factor -- the passing of the date
transforms the
milk in your mind. So you smell what you expect to smell, taste what you want to taste. You can be
daring, or not.
I always just
throw it away. The
guilt comes right after.