Hi.so I work quite long days and I'm just wondering if I were to prepare a couple of shakes before work and then refrigerated them until I wanted to drink them then how long will they last?is there a certain amount of time after a shake is made that u should drink it? I don't want to take the bars to work as the chewing motion makes me want food so this is the only option as I find using a shaker does not get all the lumps out and I don't own a portable whisk!!x