When you look at Germany and its wines, you must look first at the climate. Because it lies so far north, Germany has a shorter growing season and a cooler climate than most of the world's wine producing countries. As a result of the cool climate, there are few grape varieties that distinguish themselves and even they vary greatly in quality depending on the vintage. Nearly all of the grape varieties that are successfully grown in Germany are white. The Riesling grape variety produces the finest wines in Germany, but the variety that is most planted is the Muller-Thurgau. Muller-Thurgau is a hybrid between Riesling and Sylvaner. Muller-Thurgau ripens earlier than Riesling and is a better match for the climate is some of Germanys wine producing regions.
The major challenge to the wine grape grower in Germany is getting enough sun and heat in a season to fully ripen the grapes. Because nature sometimes does not bring the grapes to full ripeness, German regulations allow for the addition of sugar during fermentation.
While there are 13 significant wine producing regions in Germany, the best are found along the Rhine river and along the Mosel river. In each of these areas, the best vineyards are found close to the water where the heat of the day is slowly released at night. The terrain in Germany's vineyards is usually very steeply sloped. In the best vineyards, the vineyards have a high percentage of rock (often slate) in the soil. The heat of the day is absorbed in the rocks and slowly released at night.
In general, the wines of Germany can be described as having a floral bouquet and a touch of sweetness that is balanced by high levels of acidity. The aromas are brought about by virtue of the grape varieties that impart them. The sweetness in the lesser grades of wine can be brought about by the addition of sugar during fermentation and by the blending of small percentages of "suisse reserve' (unfermented grape juice) into the wine after the base wine has been fermented.
The classification system for German wines is very logical. It is based on the sugar content of the grapes at the time of harvest.
TAFELWEIN - Loosely translated as "table wine". This is the lowest category of wine and is mostly consumed within Germany. It is generally from grapes that have just barely achieved ripeness. These wines almost always require added sugar to achieve fermentation. The wines can be pleasant but are not noteworthy. They should be consumer when young.
QUALITÄTSWEIN - Loosely translated as "quality wine". This is the category of German wine that accounts for the greatest percentage of exports. The grapes used in these wines are from better growing areas. The grapes are at least ripe enough to distinguish their geographic origin although they usually, but not always, have sugar added during fermentation. These wines should be consumed within the first few years after production. These wines are also known as "QBA" wines.
QUALITÄTSWEIN MIT PRÄDIKAT - Loosely translated as "quality wine with promise". This category of wines includes the best that Germany produces. There are very strict controls and regulations applied to wines in this category. The grapes must be picked at minimum defined sugar levels and there cannot be any sugar added. 'MIT PRÄDIKAT' wines are futher broken down in the following categories.
KABINETT - "Reserve wines" - These wines can be very elegant. There is often just a whisper of sweetness and that is balanced by acidity.
SPÄTLESE - "Late Harvest" - These wines are made from grape clusters that are fully mature and picked later than Kabinet grapes. They can be nearly dry or somewhat sweet depending on the techniques of the winemaker. These are very nice wines.
AUSLESE - "Select Harvest" - Auslesen wines are full and rich and made only in the best years. They were at one time made only with specially selected very ripe bunches of late harvested grapes. The grapes are sometimes affected with Botrytis Cinerea which makes them much richer. The best wines of this category can usually age up to 15 years if stored properly.
BEERENAUSLESE - "Selected Berry Harvest" - These wines are made from grapes that are very high in residual sugar. The traditional method of harvest was to pick individual berries that were shriveled or affected with Botrytis. These are very sweet dessert wines produced in only the very best years. They are expensive and can age for decades.
TROCKENBEERENAUSLESE - "Selected Dried Berry Harvest" - These wines are very rare and result from harvesting individually selected, late picked grapes that are usually affected with Botrytis. They are a great luxury and require long aging to be at their best. If properly stored they can live (and improve) for a hundred years or more.
Other special classifications of German wines include: Eiswein (from frozen grapes), trocken (dry) and halbtrocken (half-dry). Trocken and Halbtrocken wines are usually in the QBA or QMP-Kabinett categories and reflect an effort on the part of some winemakers to produce drier wines that may be more acceptable for the international market.