Most members of the VDP (Verband Deutscher Prädikatsweingüter) are included as keywords. For all growing regions, all producers are listed before the grape variety table, a subset of which are the VDP vintners - see, for example, under Mosel. For a list of all VDP members, the VDP website is recommended. For vineyard classification and wine quality pyramid, see VDP Class ification.
Serious sources on the internet are rare - and Wine lexicon from wein.plus is one such source. When researching for my articles, I regularly consult the wein.plus encyclopaedia. There I get reliable and detailed information.
Thomas Götz
Weinberater, Weinblogger und Journalist; Schwendi