Anthony's Premium Buttermilk Powder, 1.5 lb, Gluten Free, Non GMO, Made in USA, Keto Friendly, Hormone Free

I just got this in the mail and there is no instructions on how to reconstitute it, could you tell me what the water to powder ratio is?

Why does the back of the bag say “please do not look under the bag” in the photo?

Are the cows that produce the milk given antibiotics?

Can this be frozen to extend shelf life?