"Qualitizwein mit pradikat" is a high-quality, totally natural wine.
Ripeness of grapes ranges from kabinett (dry) to spatlese (medium dry) to auslese (sweetest).
"Trocken" designates a dry wine; "halbtrocken" a medium-dry wine.
He also added that he likes the wines from the Mosel/Saar/Ruwer river regions, which present a "slatey" flavor due to the soil.
(Don M., if you are reading this, let me know if I got any of this wrong!)