For Early man, moving fire required carefully transporting it in a simple hollowed out hunk of wood.
Moving liquids had the same problem for our ancestors. Moving wine, for instance, was done in earthenware jugs of various sizes. These jugs did not transport well and were quite difficult to handle. Also, trying to move wine to cities in colder climates caused the jugs to freeze and break open, dumping their precious cargo alongside the road.
Once the white oak barrel was perfected, wine and other liquids could then be transported just about anywhere in the world.
Over the centuries, vineyards and distillers happily discovered a marked improvement in the taste and other characteristics of their wines and whiskeys when transported over long distances in these barrels.
It was soon discovered that toasting and charring of the inside of the barrels before filling created a sugary caramel layer which the liquid passed through with each rise and fall of temperature, further enhancing the taste and color.
The white oak barrel soon became so important to the making of bourbon whiskey that the United States Government enacted a federal law requiring the use of new, charred, white oak barrels in the making of all bourbon.
Much like the nomadic method for carrying fire, the white oak barrel is often considered just a disposable, unappreciated hunk of wood. However, without it there would be no bourbon, no Tennessee Whiskey, nor delicate wines for us to enjoy.
Curt Gibson--Brown-Forman Distilleries Retiree