Hi, Soy milk can remain unrefrigerated until opened. Then I believe it has the same life as regular milk. It doesn't last that long in my household as most of us have a blood allergy to dairy products. They make yogort now that you swear must be made with real milk it's GREAT!! Hope that helped.
Try Silk soy milk. It comes is in the refridgerated section of your store. I can find it at Kroger and Albertsons, but don't kown how widely available it is. This stuff is great. I buy the vanilla (they have plain and chocolate(also great)too). I drink every morning with fronsted mini-wheats. I'm sure that sounds mundane to some - but give it a try!!
My husband has 'periods' of lactose intolerance but he hates the taste of soy milk (even vanilla soymilk). You might want to try rice milk. The brand I purchase sometimes is called "Rice Dream" and Jim really likes it (you can get it at Trader Joes'). It doesn't have that 'beany' taste you sometimes get with soy milk.
And I agree, once it's opened, stash it in the fridge! It tastes MUCH better cold anyway!
Silk soy is the best!! i am addicted to it... i actually have it in place of a snack most of the time. and every morning for breakfast I also buy the Vanilla and the Plain. I actually have been telling my friends about it... and i dont usually get excited over such a small thing, but the Carbs are relatively low, and the protein is higher than regular milk and the non-lactose milks.... I use Silk soy with everything that calls for milk.