Geological exploration of the cellar system found that the soil had accumulated as a result of several major volcanic eruptions.
Although most of the walls along the wine-tasting cellar route are covered with noble mold, traces of more than 10 million years of volcanic processes and subsequent rock changes can be seen.
The cellars of Tokaj-Hegyalja – as well as the cellar of HOLDVÖLGY- are carved into rhyolite and are covered with noble cellar mold called Cladosporium Cellare. This special mold only covers cellar walls in the Tokaj region and in the regions of Rhein. This fungus plays vital role in ensuring the quality of Tokaj wines, as it is able to control the humidity of the air and also plays important role in the aging of the wines.