[6] Because of the northerly location of the Mosel, the Riesling wines are often light, tending to lower alcohol, crisp and high in acidity, and often exhibit "flowery" rather than or in addition to "fruity" aromas.
Its most common vineyard soil is derived in the main from various kinds of slate deposits, which tend to give the wines a transparent, mineralic aspect, that often exhibit great depth of flavor.
[8] It is believed that viticulture was brought to this area by the Romans who planted vineyards along the Mosel and the Rhine in order to have a local source of wine for their garrisons.
The cost of transporting wine up from the Italian Peninsula or across the Vosges Mountains and the Roman vineyards in Gaul was very high and impractical.
Viticulture was certainly flourishing in the area by the 4th century when the Roman poet Ausonius wrote a poem about the beauty of the land at harvest time.
In the winter time, the wine was heated in a kettle and drunk like a tea (a practice that still has some tradition among modern vineyard workers who drink it like coffee,[clarification needed] often with a little sugar added).
During the cold autumn the fermentation process would not be fully complete because of the low temperature, thus leaving the wine with high levels of residual sugars.
In the 18th century, the Prince-elector of Trier, Clemens Wenceslaus of Saxony, mandated that over a seven-year period every vine in the Mosel area was to be Riesling only.
[13] The 19th century saw an unprecedented era of prosperity for the Mosel wine industry under the rule of Prussia starting with the historic vintage of 1819.
[14] By the 1850s, wine-makers in the Mosel had discovered the benefits of chaptalization in helping to compensate for bad weather vintages and under ripened grapes.
The best producing vineyard sites are located along the Mosel river and its tributary where the heat from the sun can be maximized by reflection up from the water.
South and southwest facing slopes are even more sought after because of the increased exposure to direct sunlight that can aid in ripening of the grapes.
[15] The soil of the area is dominated by porous slate which has ideal drainage for the regions heavy rainfall and good heat retaining properties.
Safety is a priority for many Mosel vineyard owners with the area having a documented history of fatalities among workers while tending the vines.
During the winter, rain often causes some soil erosion, especially of the vital slate chips that are needed for their heat retaining properties.
Factors such as altitude, aspect and sunlight exposure can have a pronounced effect not only one the resulting quality of the wine but also whether the Riesling grape will even ripen at all.
However, in 2007 and 2008, the negative trend in total plantations has been broken, and the Mosel vineyard surface has seen a small increase of 59 hectares (150 acres) in two years.
The projected Mosel High Bridge will cross and affect some of the most famous vineyards prompting international wine critics and oenologists to oppose its construction.
[12] Many of the vineyards of the lower Mosel are terraced, which has led many producers to adopt the name Terrassenmosel, which sounds nicer than Untermosel in German.
The most ideal vintages allow harvest to take place between late October and mid November when the grapes can develop enough sugar to produce floral and honeyed notes.
[23] The wines of the Upper Mosel, especially along the Saar and Ruwer tributaries, are characterized by their low alcohol content in the 6-9% range with intense fruity notes and high acidity.
An obscure local poet once described them as 'Sonnenfeuer, Sternengold, Kühlen Mondlichtschein' - The fire of the Sun, the gold of the stars, and cool moonlight.
[3] Mosel Rieslings rely on a strong presence of tartaric acid to balance the grape's sugar and to help impart its fruity notes.
The Mosel is also well known for its Eiswein production with the area's characteristic high acidity coupled with the sweetness produced by the concentration of the sugars in the frozen grapes.