What is a Naturwein (“natural” wine)?

At the dawn of the 20th century, “improving” wines with sugared water, blending wines of various origins, and using ambiguous designations were widespread practices. In contrast, the  “Naturweinversteigerer” (estates that sold their “natural” wines at auction) advocated other principles. They refrained from purchasing grapes and/or wines from third parties for commercial purposes, and guaranteed the absolute purity and authenticity of their wines (Rheingau). Quality and holdings in the region’s top sites were emphasized to promote sales. They were committed to fostering and safeguarding the quality ideals of non-chaptalized, natural wines (Rheinfpalz).

Why Naturweinversteigerer?

Those fortunate enough to own parcels in top vineyards and have sufficient capital to not have to sell their wines in bulk marketed their finest wines at auction. As early as the 18th century, renowned wine estates along the Rhine held auctions. To participate, wine brokers and merchants had to travel to the respective estates. By the end of the 19th century, several good vintages and a concomitant, dramatic increase in demand for German Riesling natural wines led to a surge in the number of wine auctions. At this time, wine estates from the Mosel, Saar, and Ruwer formed an auction consortia and held their auctions jointly. Members of the Vereinigung Rheingauer Weingutsbesitzer coordinated their schedules a short time later. The union of regional associations in 1910 served to coordinate auction schedules in the individual regions so that members of the then-founded Verband Deutscher Naturweinversteigerer (VDNV) no longer had to compete against one another to attract brokers and merchants to their respective auctions. Auction conditions were also harmonized. Both measures strengthened the position of the Naturweinversteigerer vis-à-vis other members of the wine trade who were relatively well organized by then.

Membership directory of 1926

The membership directory published 1 April 1926 not only listed the members of the regional associations in the Rheingau, Rheinpfalz, Rheinhessen, and Mosel-Saar-Ruwer. It also included members of Naturweinversteigererassociations in the Nahe and Baden regions. In the meantime, a second attempt to form a similar association in Franken failed. Nevertheless, by 1926 the VDNV comprised 216 member estates that jointly cultivated ca. 3,600 ha (nearly 9,000 acres) of vines. The vast majority were located in Rheinpfalz: some 52 estates, with 565 ha (1,400 acres) and 20 cooperative wine-growers’ associations with 1,353 ha (3,343 acres). As such, about a third of all members and more than half of all vineyard holdings were from the Rheinpfalz. The 49 members from the Rheingau cultivated nearly 605 ha (1,500 acres), while the Mosel-Saar-Ruwer had 54 members with 485 ha (1,200 acres). Although there were only 24 members in Baden, including a few cooperatives, their holdings amounted to an impressive 377 ha (932 acres). The eight members from Rheinhessen had 106 ha (262 acres), and the nine from the Nahe, ca. 132 ha (326 acres). In all, the national association was remarkable in that its members had holdings in the finest sites of their respective regions.

Wines at the official opening of the German Wine Museum

The wines served at the official opening of the first German Wine Museum in 1927 as well as at the festive dinner at the Hotel Porta Nigra/Trier were donated by the by the members of the Trierer Verein von Weingutsbesitzer der Mosel, Saar, and Ruwer. Among the 16 wines served, the majority, as usual, were from the Saar Valley. Numerous wines were from the best vintages of the last two decades, above all from the 1921 vintage.

Grosslage vs. grosse Lage

In German, “gross” (incl. grosses, grosser. grosse) means large as well as great.
A “Lage” refers to a vineyard site. (Plural: Lagen)
A “Grosslage” is a German viticultural appellation of origin that refers to a large vineyard site, usually comprising several "Einzellagen” (individual sites). It was one of the designations created with the German wine law of 1971. As of 2006, there were some 170 Grosslage sites in Germany, ranging from in size from 600 to 1,800 ha (ca. 1,500 to 4,500 acres). 
A “grosse Lage” is a consideraly smaller, great or top vineyard site. It denotes the origin of the highest quality of wines within the in-house classification of the VDP.