Effect of the plant sink/source balance on the metabolic content of the Vitis vinifera L. red grape

•Bunch thinning does not increase the contents of molecules of interest in the grape.•Reducing yield induce a loss of metabolites with no fruit quality gains.•Aromatic precursors represent a small fraction of the non-structural C of the grape.•The manipulation of sink/source ratio does not change the metabolic flows to the fruit.