Here's what the Vadai company has to say about Hungarian oak:
Sourced from the steep, rocky hillsides of the renowned Zemplen forest, the trees grow in a unique soil with a high mineral content. The wood used for Vadai's barrels is selected from 100 year-old trees that is air-dried for three years before being crafted into barrels.
The finished barrels have a high perceived-vanillin content along with bittersweet chocolate, subtle black pepper, roasted coffee, and leather notes. They gently structure the wine in a restrained and elegant way that never steps on the fruit (a quality that makes the Vadai barrels ideally suited for smaller sized lots where overpowering the wine might be a concern).