DLG was founded in 1885 by Max Eyth, has over 23,000 members as of 2011 and is headquartered in Frankfurt am Main.
[1] Its main purpose is to promote technical progress and scientific advances in the food and agricultural industry, including setting standards.
[3] In the area of German wine, DLG has been responsible for devising the assessment scale used for official classification as well the medals and awards that are handed out regionally and nationally.
This is a five-point scale where the wines are assessed blind (i.e., the tasters don't know the identity of the wine in the glass) by a panel and given points in the three categories bouquet ("nose"), taste and harmony.
The category "harmony" refers to all sensory impressions, including color, and is concerned with the overall balance between sweetness, acidity, alcohol and "body"/mouthfeel of the wine.