I'm asking this because the majority of whiskey's are aged for 6+ years and I would think that people would not think to leave it for that long. Even leaving beer for a couple of weeks seems a bit long for them to leave it.
I'm not sure if this is exactly what you were looking for, but here is a recent story about Ancient Egyptian Beer. The story describes the recently discovered tomb of "ancient beer-maker Khonso Em Heb" which contained a 3200 year old recipe for making beer, which was brewed from barley. Professor Poo Mun Chou describes this brew, and ancient Egyptian beer in general:
While it's a close cousin to modern beer, it's manufacture was more primitive and they had to use a tube to extract the liquid from below which would have had a fermented layer of substance floating on the top of the jar... it would have had bubbles.