29 May 1992 New Zealand Climates Offer Enormous Grape Growing Potential

Overseas wine show successes enjoyed by New Zealand entries indicate the enormous viticultural potential offered by this country's climates, says Lincoln University grape scientist Dr David Jackson.

"Wine quality reflects the skill of the grape grower and winemaker, and the poor wines produced prior to the 1970s were partly due to grape growers choosing wrong varieties and neglecting some of New Zealand's best climates," he says.

"In addition, grape growers and winemakers were less knowledgeable then than they are today. But no matter how capable the viticulturist and oenologist, wine ultimately depends on the choice of the most suitable locations. With grape growers and winemakers of superhuman ability, Scotland would never rival France. It's too cold and grapes do not ripen there!"

Dr Jackson believes the climates of New Zealand have close similarities to those of famous European wine areas such as Bordeaux, Burgundy, the Rhine, Moselle and Northern Italy.

Using a climatic index called the latitude temperature index (LTI), Dr Jackson equates New Zealand grape growing districts with their European counterparts. The index was developed at Lincoln University by Dr Jackson and meteorologist Dr Neil Cherry.

"The southern parts of New Zealand such as Central Otago, Queenstown/Wanaka and South Canterbury have climatic indices similar to Alsace, selected slopes of the Rhine, Moselle and Burgundy. They could be expected to produce fine Rieslings, elegant Pinot Noirs and Chardonnays," he says.

"North Canterbury, Nelson, Blenheim and Martinborough have indices similar to Southern Burgundy, Beaujolais and Bordeaux. Pinot Noirs, Beaujolais style wines together with Chardonnay and Cabernet/Merlot blends would be expected to excel. Sauvignon Blanc and Semillon of a dry or late-picked botrytised styles would be successful.

"Further north in Hawkes Bay, Gisborne and Auckland, we attain indices similar to the Rhone Valley and northern Italy. The additional warmth of these districts means most varieties will grow, but greatest success might be achieved with those with higher heat demands such as Cabernets and Shiraz or the very adaptable Chardonnays and Sauvignon Blancs."

Dr Jackson is impressed by the fact that New Zealand's New World competitors in North and South America, South Africa and Australia are producing wine in generally hotter conditions than the classical European districts.

"This does not mean they do not produce good wine, but the wine will be different in style and may not always suit the European palate.

"There are cooler New World areas with similar LTIs to Europe, but unlike New Zealand they often have serious climatic problems. Canada and Washington state for example suffer excessive summer heat and very cold winter temperatures which sometimes kill the vines. Oregon often has wet springs and autumns and hot dry summers, and southern South America is cold but wet. North eastern USA is rather too warm and humid and also may suffer winter freeze."

While the New Zealand wine industry has its problems at the moment, Dr Jackson has enormous faith in the future and believes the best wine areas of New Zealand will have prestige equal to the classical districts of Europe. There will be an increasing interest by overseas investors in the New Zealand wine scene, he predicts.

• In June, Dr Jackson travels to the United States to receive an award from the American Society for Enology and Viticulture for the best research paper published in the 1991 volume of the American Journal of Enology and Viticulture.

Ian Collins, Journalist, Lincoln University, Canterbury, New Zealand