The real reason I thought to post about this was because I love their artwork for everything, but it seems I like the product just as much.
"Like ROOT and SNAP, RHUBY is based on a centuries old Pennsylvania recipe and is totally unique in the marketplace. There has never been anything like it…at least not since 1771. This is the year Ben Franklin sent John Bartram America’s first rhubarb seeds. Bartram proceeded to make a delicious garden tea with rhubarb, beets, carrots, lemon, petitgrain, cardamom, pink peppercorn, coriander, vanilla, and pure cane sugar. We took this recipe and turned it into a spirit!"
They have a few recipes here, although I'm not sure when it's for sale. Hopefully I can find it soon!