How to classify German wine

Gary talks about the QMP,QBA and many other things that have to do with German wines and how they are classified. This is important to know if you want to try different wines from there. Besides the breakdown, Gary also tastes 2004 Von Hovel Qba Riesling, 2004 Willi Haag Brauneberger Juffer Riesling Kabinett, 2003 Johann Haart Piesporter Goldtropfchen Riesling Spatlese, and 2004 St.urbans Hof Ockfener Bockstein Auslese Riesling.