There are many ways to use oak in winemaking, and with the WinePod you have two choices: barrels or additives.
Notes from the winemaker: After the grapes, the next most important big thing is the choice of oak. First, the choice of whether to use it at all. Second, the choice of using barrels or some substitute. And third, whether to use French, European or American oak. Each one of these choices strongly impacts how the wine will turn out, and poor choices here can result in very poor outcomes. My advice is to err on the side of caution if a little is good then less is better, not more.