The German word for "white wine" is Weißwein. Also the different spelling: Weisswein.
"German white wine" means "deutscher Weißwein" / "deutscher Weisswein" in German.
If you are asking for different types of German white wine: just click the links I added under "related links" below.
One of the most popular types of German white wine is Liebfraumilch. It is a semi-sweet, affordable brand of wine.