It is not the flesh but the skin of the grape that gives colour - and flavour. Hence some drinkers find reds more ‘satisfying’ - simply because they have more flavour sources! While whites have apple/citrus flavours of pulp, these are ‘built over’ in reds by stronger red and black fruit, spicy and earthy flavours caused by maceration (soaking/fermenting on skins). This ‘leaching’ is almost exclusive to reds, also leading to fuller texture and weight of solids (phenolics). The most important phenolics - besides colour compounds - are tannins. From both skin and pip, the quality of tannins help red wines to age and determines their style as soft and fruity (low tannin) or firm and structured (high tannin).