The Romans... in sulphuro veritas?

The systematic use of sulfur did not occur until the late Roman Empire.

Celts in what is now France had already invented the oak barrel before Caesar conquered Gaul in the mid

Caesar conquered Gaul in the middle of the first century B.C. (the wooden barrel was unknown to the Romans).

Celts traded in wine and transported it in barrels, but found,

that the contents were often tipped after arrival at the destination, i.e. turned into vinegar.

had become vinegar. So they began to sulfurize the wine when necessary, and it remained so until the 16th century.

so.