Beer Brought Back to Life (Live Science)

Unlike most multi-celled animals who disintegrate after death, single-cell organisms can go dormant under the right conditions.  See "Amber Ale: Brewing Beer from 45-Million-Year-Old Yeast"

Sydney Cove Shipwreck Beer Bottle (via ABC.au)

Just released today is the announcement of the recreation of 200 year old beer aboard the wrecked H.M.S Sydney Cove.  See "Oldest Beer Brewed from Shipwreck's 200-Year-Old Yeast Microbes" from LiveScience.

Theoretically, Saccharomyces could very well be suspended in the interior wax coating of Neolithic and Bronze Age beakers.  Even if the wax is not visible to the naked eye, small globules may be present under microscopic examination. If wax is present, Saccharomyces is probably present as well.  The real work would be attempting to isolate and reanimate the organisms.  

There's several things we could learn about five thousand year old beer.  The first is the sophistication level of brewing.  One way to know this is by actually tasting the beer.  The other is through genetic analysis.  If multiple strains are present, we might learn about the alcohol content %, the time of year certain strains were used, and what they were used for (mead, barley beer, etc)

Chemical analysis will also do one other thing that I've suspected, the presence of oak lactones would mostly prove that log barrels (as I've hypothesized) were used to ferment and store beer instead of clay pottery.  (See here)