The Quercus alba or white oak, more commonly known as American oak, is used in the production of Bourbon barrels. Utilizing trees that are at least 90 years old is a common and accepted practise. The cellular structure has bubble-like cell structures within it called tyloses. These tyloses bulge into the cavities of the xylem, which is the tube of moisture-conducting cells, and prevent water from moving through the system. Because of the tyloses, the wood is extremely impermeable to water, even when cut into thinner staves, making it ideal for the production of barrels using machinery. Before the United States took over the market with machine-produced oak casks on a scale that had never been seen before, European oak casks that were hand-cooperated maintained their dominant position until the beginning of the twentieth century. Bourbon Barrels are more commonly used in our furniture.