(Science20) - Since my last name means "grapes" in Italian, it is fitting that my father and brother are both amateur winemakers. While my dad stubbornly sticks to medieval techniques, my brother, a chemical engineering consultant, makes use of science. But although our understanding of winemaking has deepened, and although additives serve an important purpose, the basic process has remained unchanged for about 6000 years. Commercial winemakers who rely on grape suppliers and hobbyists are both at the mercy of the harvester, who exercises control over the most critical stage of winemaking. The concentration of various grape ingredients that will impact the taste of wine vary significantly.