We don't go thru a lot of milk. Occasionally I have milk in my cereal, or when I need it for making something. Mostly, I just use it for coffee. I have noticed in the past 6 months that the sell by date for organic milk is months after the 'normal' milk. For instance, I bought milk today that doesn't expire until May 20th. At first I was skeptical, but the organic milk hasn't turned the way normal milk does, even after 2 weeks after the sell by date.
As the goofy scientist I am, I can only think that there is something that isn't added to the milk, or that there is some treatment that the organic milk is/isn't gettng.