Maybe, but they did pull the barrel from the museum and I'd presume they tried to find one that hadn't been used in living memory. Even if it's ONLY 50 years ol

Maybe, but they did pull the barrel from the museum and I'd presume they tried to find one that hadn't been used in living memory. Even if it's ONLY 50 years old it's still quite the biological time capsule. It should be verifiable though, as S. Cerevisiae is a well understood organism and the rate of mutation of various genes is well understood. They could compare to a number of yeasts form the area and if it's related, get a rough estimate of the age by working backwards.