A selection of producers of vintner‘s mulled wine can be found here: List of producers 2018 (pdf)
The basis for a tasty mulled wine …
… is a good red or white wine, preferably from one of the 13 German wine-growing regions, as these are fruity by nature and need only few flavouring ingredients. Additionally, if you choose a semi-dry or semi-sweet wine, you will need to sweeten your mulled wine only a little. Suitable grape varieties are Spätburgunder, Dornfelder or Portugieser. For white mulled wines you can use aromatic varieties such as Bacchus, Kerner or Müller-Thurgau.
Tips for making mulled wine
When warming the mulled wine, you should take care not to heat it too much or even let it simmer, as the delicate fruit aromas will be lost. From a temperature of 78 °C the alcohol will evaporate, too.
What to pay attention to
Only if producers have made the mulled wine themselves and from their own wines, are they allowed to call it “vintner’s mulled wine” (Winzer-Glühwein) and can state “wine estate” (Weingut) or “winegrowers‘ cooperative” (Winzergenossenschaft) on the label. German mulled wine is always 100% made from domestic base wines.
Legally, mulled wine is a flavoured beverage containing wine, made exclusively from red or white wine and sweetened and flavoured. The addition of alcohol as well as water or colouring is prohibited. The actual alcohol content must be at least 7% vol. and less than 14.5% vol.
Background: Popular winter drink
List of producers 2018 (pdf)
SOURCE: The German Wine Institute : Wines of Germany Press Releases