Depends really. I have one of those blender cups with the spring ball that helps mix it but it doesn't always work well. It's best to use a spoon or a blender to mix it cause that shit will explode.
I had just added the coffee about 12oz and closed the lid and shook it up and when I opened it it blew hot ass coffee everywhere! It taste great though, I've used creamy vanilla protein too and I was killer.