To European colonists, the Marlborough region in New Zealand must have looked ideal for grape-growing: striking hillsides offering every thinkable variation of aspect, gradient, exposure and soil are bathed in clear bright sunlight and kept fresh by chilled ocean breezes. To present-day European tourists, those hills still look perfect for vines – and yet most plantings are on the unleavened plains that run between these mountains.  The Waihopai river district is one such parcel of land, and Winegrowers of Ara is the largest operator therein. The terrace they occupy is a wicket-flat expanse of 1,600 hectares, currently home...