Due to the rivers vicinity the soil at Unterganznerhof is called alluvial soil. The vine soil is of porphyritic origin. Hundreds of years the farmers have fought against the river to prevent it from eroding the vineyard soil.  For this reason, a protection wall, dating back to 1779 still surrounds the entire wine estate and protects it from possible flooding. The light structure of the soil enables it to be rapidly warmed in the spring and permits ideal drainage. The complex mineral composition of this profoundly deep set soil offers excellent vegetative conditions and give the Unterganzner wine its unique special character.