Term (also de-stemming, reeling) for the removal of the grape skeleton (rapping) or loosening of the berries from the grapes. This is to prevent the tannins, which are particularly unpleasant in green grape stems, from getting into the grape must. In earlier times, the grapes were mostly processed in their entirety, as manually removing the stems was too laborious and time-consuming. A "G'rebelter (wine)" used to be colloquially regarded as a special quality in Austria. There is also a "Viennese song" about it, which is often sung at the Heurigen (Buschenschank) in Vienna (Aber g'rebelt muss er sein).
For me, Lexicon from wein.plus is the most comprehensive and best source of information about wine currently available.Egon Mark
Diplom-Sommelier, Weinakademiker und Weinberater, Volders (Österreich)