Turns out that getting enough wireless power to do something useful through a fair amount of distance (i.e. wood staves) isn't trivial...it took some work! Once we had a usable prototype though, we set out to see if we could show the world (er, ourselves) that all of our goals and assumptions could be validated with some actual spirit in some actual* barrels (we've since learned that 2L barrels are only "actual" to the smallest of home-crafter, but baby-steps!)
The barrels we used were 2L medium char vinegar barrels (large cork opening on the barrel head), and at this scale we could justify buying enough 80 proof unaged whiskey to fill a couple of these barrels.
We decided to let the experiments run side by side for a couple of weeks and we took small samples every day for pictures. It was easy to see the agitation within the barrel (which was the goal). Sampling at the end of the experiments (below) verified that we were on the right track.