Janice McDonald, Chief Winemaker at Howard Park, one of Australia’s leading wineries, explains why. “We pick at night because it’s the coolest part of the day. Unusually that is just before sunrise. When we talk about the night picking we are talking about machine picking, as it is not possible to hand pick at night. Pickers would lose fingers!”
Janice explains the science behind night picking. “We are trying to minimise the oxidative impact of the enzymes in the grapes. There can be a particularly strong reaction in white grapes with strong aromatics such as riesling or sauvignon. We want to slow down the activity of the enzyme.”
Leonard Russell, Viticulturist with Watershed Wines, the highly awarded Margaret River winery, adds that “it’s about the optimisation of the fruit. When a machine picker shakes the berries off the vines it slightly damages the fruit. Like if you take a bite from an apple and leave the apple out it turns brown. The equivalent with grapes would be a sultana flavour. By picking at night when it’s cool, we are slowing down this effect. Otherwise fermentation could start before the grapes reach the winery.”
“So picking grapes at night when it is coolest, allows the winemaker to benefit from a natural chilling effect which protects the freshness of the grapes and the purity of the fruit flavour.”
Ryan Aggiss, Chief Winemaker at Aravina Estate, agrees – citing the favourable impact on colour, flavour, and the aromas from night picking.