how long can i keep boxed milk in the refrigerator after opening?
Debbie W. | Oct 24, 2005. I bought some Silk brand vanilla soymilk 3 or 4 weeks ago, and opened it right away. This is the first time I have purchased soymilk. The stamped date on the 1/2 gallon container is 12/8/05, but the container also says that it will stay fresh in the refrigerator for 7-10 days after opening. I had some late last week on cereal, and it still seemed fine. How do I know when I can't drink it anymore?