Protein expression from berry skin of four different red grape biotypes was compared at a proteome-wide level by bottom-up shotgun proteomics, label free quantification and MaxQuant-assisted computational analysis. Red grapes were from a purebred Vitis vinifera (Aglianico cv.), a V. vinifera (local Sciascinoso cv.) grafted onto an American rootstock, an interspecific hybrid (V. vinifera × V. labrusca, Isabel) and an uncharacterized red grape with some hybrid lineage, as demonstrated by the presence of relatively high amounts of anthocyanidin 3,5-O-diglucosides. The aim was assessing the differences among red grape biotypes at a protein expression levels, also addressing the possible effect of the grafting on the phenotypic expression of some key metabolic enzymes in grape berries.