Just a quick update the 2 30ml both ended up holding the flavor for more than 3 days going on 6 days now and tastes just as good as day 1. Thank you all for the great suggestions. I will be definitely keep the caps on from now on, seeing as that might have been the main culprit. Otherwise the one I used the milk frother on for whatever reason just seems to have a fuller flavor than the same exact mix that was just shaken. 
Ohh well, will keep experimenting with the frother. For now I'm just happy the flavors are holding true. Thanks again.
Ohh well, will keep experimenting with the frother. For now I'm just happy the flavors are holding true. Thanks again.
