Leading wine chemist at the University of Auckland, Professor Paul Kilmartin, is developing sensor technology that would begin the winemaking process immediately after harvest – as soon as the harvested grapes are on their way to the winery.

The sensors would monitor antioxidant levels in the grapes and juice during transport and potentially allow levels to be adjusted.

For Sauvignon blanc, adjustment of antioxidant levels immediately after harvesting is crucial in the winemaking process because they help produce the distinctive passion fruit aromas the wine is famous for.
With transport times to the winery up to two hours, the ability to make adjustments while the grapes are in transit could make a vital difference.

Adjusting sulfur dioxide levels as soon as possible after harvest is crucial to the development of complex sulfur-containing compounds that give the wine its distinctive aromas, particularly the intense tropical aromas we associate with this wine,” Professor Kilmartin says.

“Sensor technology would give winemakers another option to ensure that oxidation is controlled right from the time the grapes are picked no matter how far they have to travel to the winery.”

Professor Kilmartin and his team have made significant advances in recent years including the discovery that machine harvesting – as opposed to hand-picking – produces higher levels of aromas characteristic of New Zealand Sauvignon blanc.

Other research has shown that cold storage can triple the shelf-life of Sauvignon blanc by reducing the loss of characteristic tropical fruit aromas over time.