ya i typically tell people that the window is 30 to 45 min but the sooner the better. Even if its just a shake with some oats or if i have some karbolyn on hand il have a scoop of that in my shake, right after you last set or hell i usually start drinking it during my last lift sometimes. the only time i don't hit this window is when I'm dieting, but i will make sure i drink 10g of bcaas during the post workout cardio. At that time I'm not concerned with gaining muscle I'm more concerned about burning fat and keeping the muscle i worked hard for.
i heard people say there is no real "window" but i don't believe that. as soon as you can get protein/carbs in post workout the better
EAT BIG TO GET BIG