The "GG" on the label stands for "Grosses Gewächs", which means great growth (equivalent to the French grand cru). Since this is a VDP-only term and not yet sanctioned by the German wine law it can't be mentioned on the label. Hence the "GG".
The Marienburg has a medium golden color. The nose is very pure and mineral, with a light aroma of ripe and concentrated apple, lychee and quince.
It is dry on the palate, with medium(+) acidity. The alcohol is high (13.5%), but I wouldn't have guessed if I hadn't read it on the label. It tastes as mineral as it smells. And the balance in this wine is sublime. It is a terroir wine par excellence. The strong mineral taste is embedded in concentrated, yet elegant flavors of bruised apple and bitter grapefruit. It feels light and soft and then densely mineral and concentrated. It oscillates. Immensely appetizing and lasting through a subtle but very long length. Drink now through 2020.
The 2007 Marienburg Riesling Grosses Gewächs from Clemens Busch is not as baroque and peculiarly ornate as Busch's Rieslings often are. It is focused more on its mineral character, which is clean, elegant and mature. Great Riesling!