Translated as ice wine, eiswein is a specialty wine that is a rare find. The reason this wine is so special relates to the process of how it is produced. During the frozen months of winter, frozen grapes that are very ripe are picked by glove-covered hands so the grapes stay frozen, as described in "The Wine Bible" by Karen MacNeil. When the frozen fruit is pressed, the concentrated juice is filtered from the ice, which is all the water found in the grape. Since the water is removed from the grapes the concentration of juice results in a wine that is especially sweet with a high acidity level. In order for the process to be effective, the grapes must be frozen naturally on the vines. German vintners use any variety of grape, such as riesling and pinot noir, to make eiswein.
Beerenauslese, also called BAs, is a rare and expensive German style of wine. Grapes are allowed to become extremely ripe and develop the noble rot called Botrytis cinerea before they are hand picked. In fact the name indicates berries that have been hand picked rather than cutting entire clusters. The noble rot is a gray fungus that can destroy a crop of grapes but is utilized by picking the grapes at just the right time. According to MacNeil, the resulting wine has a deep honeyed richness in flavor compared to other sweet wines. BAs are typically served as a dessert wine.
A more extreme variety of BAs, Trockenbeerenauslese is a sweet wine that is the most expensive wine produced by Germany. Also known as TBAs, this variety is the richest and sweetest German wine. According to MacNeil, TBAs are only produced with grapes that are grown in the best vintage years. These grapes are allowed to develop botrytis until they are shriveled on the vine to resemble raisins. Grapes are hand picked and require more manual labor than BAs. In one day, one person will pick just enough grapes to make one bottle of wine. The extreme concentration of sugars found in TBAs causes fermentation to be mild, and the alcohol content peaks at 6 percent in these wines.