The effect of machine harvesting on wine quality has been the subject of much scientific study, commercial experience, and popular conjecture. The majority of studies have shown that sophisticated mechanical harvesting has no negative effect on wine quality, and some have even argued that there is a positive effect. Certainly most forms of machine harvesting damage some grapes so that parts of berries and bunches are mixed with the juice of broken berries. However, the juice can be protected from oxidation by sulfur dioxide addition, especially if moved quickly in a closed container to the winery. This problem can be minimized by harvesting at night, a practice widely adopted in hotter wine regions where grapes harvested by day can arrive at the winery at over 40 °C/104 °F. Indeed, in these circumstances, machine picking at night is a bonus for wine quality in comparison with hand harvesting by day.