J.L.
Soy milk doesn't really expire at all. Some users say the liquid "curdles" which isn't true. Soy milk isn't milk, so it doesn't curdle. It condenses into a thick slush which is the soy bean granules, but that's if you leave the cap open. As of right now we have three bottle of silk open in the fridge which expired on February 14th. I drank almost a whole carton and I feel fine. This isn't the first time we've allowed silk to sit past it's false "expiration" date.
Yes, the Silk expiration date is just a marketing ploy to get you to buy more. It means nothing since we regularly leave cartons open or sealed nearly 2 months after the date that is printed on the top. The longest carton we've had was last year when we went on a 3 month vacation. The Silk carton stated it expired in April and it was still fresh and drinkable in late July.
They say finish it within 7-10 days and that it remains "freshest" during that 1 week period. That's obvious, it'll always be fresher on day 1 than on day 2 and on day 10 than on day 11. They just don't mention it's still "just as fresh" on day 90. But of course since they use the word "milk" on their label people get an automatic sense of an ultra perishable liquid, which is not true.
Hope this helps and don't throw away your "expired" Silk!!!!!