. "Rotberger is a wine grape variety. Its parentage is not known with certainty but it is thought to be from a cross of Trollinger and Riesling grapes). Dr. Heinrich Birk (1898-1973) produced the cross at the Geisenheim Grape Breeding Institute in 1928. It is used to produce fruity, early maturing light red wines in cool-climate areas. It is often best drunk when young and can be used to produce a ros\u00E9 or sparkling wine."@en . . . "Rotberger"@en . . .