The aim of Erland Happ is to produce wine with the best possible flavour.
Happ has two properties, one of 28 ha at Dunsborough, 250 km south of Perth, WA, and a more recently purchased property of 148 ha some 100 km further south at Karridale. He grows Cabernet Sauvignon, Shiraz, Merlot, Chardonnay and Verdelho with small amounts of Tourga, Tinto Coa and Souzio on 17 ha at Dunsborough and he has planted more than 29 varieties of wine grape at Karridale.
A former teacher and potter, he took up land for the Dunsborough vineyard in 1978 and has established a reputation for producing a range of quality wines in one of Australia’s premium wine growing districts. But he wants to produce even better wines.
“Scientific vine management and clever winemaking will carry the industry so far, but it is the quality of the raw material which places an upper limit on what can be achieved,” he said.
“About two years ago I had a hunch about the effect of high heat loads during maturation, in destroying grape flavour, and I have been able to demonstrate that the best quality wines are produced under uniformly low heat loads, in the last month, in France, Australia and New Zealand,” he said.
“Flavour is not quantifiable, but in the long run quality, price and palatability are strongly related.”.
Happ argued that if we examine the climate in areas where expensive wines are regularly produced it should be possible to get close to defining the best environment for a particular variety of grapes to produce optimum wine quality.
He believes that the weeks immediately prior to berry maturation are critical to developing flavours.
“Typically flavours accumulate in the last week or so before fruit is ready for picking. Some varieties, such as Muscat are highly aromatic. You can pick the effect of weather events up to three weeks before harvest,” he said.
The substance which give wines flavour are mainly low molecular weight aromatic substances. They are highly volatile and fugitive – they are easily lost from the ripening grape.
Fruit grower’s experience shows that flavours are best preserved in all fruit at lower temperatures. For that reason fruit of all kinds is rapidly cooled after picking and stored under cool condition prior to consumption.
Happ believes that once flavour substances are lost from grapes they are never completely replaced. Therefore even a short period of high temperatures – heat spikes – during ripening can lead to significant loss of flavour in the harvested grape. Although fruit flavour is more likely to depend on fruit temperature than air temperature, the two statistics are closely related.
He concluded that minimal heat in the vineyard during the final month of maturation is critical to retaining the flavour-containing substances in the berry prior to winemaking.
Erland draws on thermal evidence from other wine regions including France, New Zealand and other parts of Australia to support his hypothesis.
The availability of cheap and robust temperature loggers in 1995 provided him with an opportunity to gather data to support his hunch. The loggers can measure and record temperatures at 20 minutes intervals over a period of up to three months. The data is then downloaded to a personal computer and analysed using a spreadsheet.
“Each logger can store more than 7,000 data points. In contrast, a conventional maximum-minimum thermometer can only store two bits of data,” Happ said.
Each logger is housed at vine height (about 1.2m) in a ventilated metal housing, which allows free air circulation. A white polystyrene disc protects the logger from radiant heat reflected from the soil surface.
In the first year Happ placed 15 loggers in vineyards between Bremer Bay and Perth with the cooperation of their owners. He later contracted his study area to the south west of Western Australia along the coast between Dunsborough and Albany.
On his home vineyard at Dunsborough he also has a weather station which records temperature, humidity and wind speed at 10 minute intervals.
His plan is to gather comprehensive climate data and use it to match vineyard climate to grape variety for optimum flavour development and retention.
“Grape varieties vary in their response to heat. Some, such a Pinot Noir, are extremely thin skinned; under heat stress they raisin, quickly become dehydrated, high in sugar and with ‘green’ flavours locked inside.”.
“Chardonnay, on the other hand, is not so susceptible to heat damage and will produce wine of a sort in all climates.”.
Happ has chosen Dijon in Burgundy as his benchmark premium winegrowing environment. Dijon has a reputation for producing excellent, high priced Burgundies. The average maximum temperature at Dijon during the month prior to grape maturation is 22Â°C. This temperature Happ chose as a criterion when estimating heat loads on maturing grapes.
“A lower temperature would be less sensitive to differences between climates. So I chose 22Â°C. It is a neat balancing point which provides maximum discrimination between sites.
“A higher base temperature would not show all the advantages of cooler climates.”.
Dr John Gladstones, in his seminal work Viticulture and the Environment classified grape varieties into eight groups based on the degree day requirement between 10Â°C and 19Â°C to bring the fruit to maturity. This classification is crucial to Happ’s matching of climate with variety.
Gladstones was restricted to published temperature data based on very limited numbers of observations. Happ claims average temperatures calculated from 72 observations during the day provide a better guide to relativities between sites, but heat loads in degree hours above 22C is much better at discriminating between wine growing environments
Happ points out that Australian grape-growing climates are very different from European climates. Major vineyard areas are found at latitude 34Â°S in Australia, which is comparable to Algeria in the Northern Hemisphere. In contrast the Burgundy region is at latitude 46Â°N and is buffered from Saharan influences by the sea and major mountain ranges
Hot easterly winds from the central desert can produce damaging heat spikes in coastal vineyards from Western Australia to Victoria.
“Under Australian conditions, heat load is a better measure of heat spikes than mean temperatures,” he says.
The change in climate in Europe from say Dijon to Marseilles (450 km) is about the same that between Frankland and the South Coast of WA, some 140 km. Therefore a careful measure of the environment is more critical in Australia than in France.
Happ is evaluating grape varieties at his Karridale property, casting as wide a net as he can given the limited genetic resources available in Australia.
“There’s no better place for a vineyard than Karridale with its maritime climate,” he said. Temperatures don’t fall very much. In June, July and August they are 2Â°C higher than Dunsborough and the hot months are cooler. It’s warm enough to ripen anything and not too hot so that heat spikes destroy flavour.”.
Dunsborough normally experiences some ten days of hot dry conditions during grape maturation. In contrast at Karridale one or two similar heat spikes are the norm.
Happ’s conclusion is that appropriate land management for quality wine production begins with selecting sites, choosing varieties and predicting ripening times for each combination of site and variety.
The next step is to check the temperature for one month prior to ripening to look for hot spells which might reduce the content of flavour producing substances. Then the grower can choose the best combination of site and variety to produce quality fruit.
The only objective way to determine if Happ’s innovations have succeeded in improving wine quality is to taste new wines, yet to be released. He maintains that the differences are obvious, even to the untrained palate.