After mixing powder with liquid, how long is the mixed shake or smoothie safe to drink? August 20, 2020 22:54 Updated If not refrigerated, after mixing the powder with liquid to make a shake/smoothie it should be consumed within 2 hours. If refrigerated after mixing, it should be consumed within 24 hours. Related articles After opening, how long is a ready-to-drink shake safe to drink? What is the shelf life of Orgain protein powder? I see tiny black specs or dots in my protein powder, what is that? After opening, how long is the protein powder safe to consume? Why do you use erythritol as a sweetener?