Understanding Terroir

Auckland University scientists are working with winemakers attempting to solve the puzzle of terroir by researching yeast varieties indigenous to West Auckland vineyard Kumeu River Estate. The study has uncovered close to 100 new varieties of wine yeast, each of which is specifically indigenous to the greater Kumeu wine region and unlike any other strains of yeast in the world, according to lead researcher Dr Mat Goddard. He believes this scientific breakthrough could have wide-ranging benefits. “The use of New Zealand-specific wine yeasts may prove a powerful tool to further differentiate New Zealand wine,” Goddard said. “They more faithfully reflect the New Zealand sense of place than overseas wine yeasts.” Kumeu’s winemaker Michael Brajovich believes a commercial yeast strain tends to dominate a ferment, which often leads to a lack of varietal definition and lessens the expression of the vineyard. But subtle wild yeasts seem to let the geography show, he says. “With wild yeasts, the yeast character retreats a lot, allowing the expression of variety and vineyard,” he says. “This makes the wine much more expressive of its place. It allows the vineyard to show better. That, and because the yeasts are unique to us, which has been shown through DNA analysis, they are, arguably, part of the terroir.”