(Decanter) - A summer heatwave means there is a high potential alcohol level for Alsace Riesling wines in several areas, say producers including Hugel & Fils, but the overall crop looks healthy. 

A July heatwave that saw temperatures top 40 degrees celsius  (104˚ F) means potential alcohol from the 2015 wine harvest is above 16% in some cases, said the Alsace Wine Council (CIVA). Early reports suggest the 2015 crop is healthy with little sign of disease.

A ‘bulldozer’ Alsace 2015 vintage

‘It’s a bulldozer vintage,’ said Guillaume Mochel, of Domaine Frederic Mochel, northern Alsace. High  alcohol may leave too much residual sugar to make dry wine from his vines in grand cru Altenberg de Bergbieten.

But, he will make non-grand cru dry Riesling with grapes at 14.5% potential alcohol.

Further south, in Riquewihr, Jean-Frederic Hugel at Hugel & Fils said the domain doesn’t plan to use Riesling from its Schoenenbourg [grand cru] vines – apart from late harvested grapes –  and reported potential alcohol up to 16.5%.

Hugel will buy grapes from cooler areas or higher yielding young vines to make non-grand cru dry Riesling in 2015. ‘Luckily we have back vintages to 2008 that we can sell,’ Hugel said.

Trimbach optimistic

Others, including Jean Trimbach of Maison Trimbach, were more optimistic. ‘The Rieslings picked at 15 and above potential alcohol represent only a very small percentage of the volume,’ he said. ‘Our grand cru Schlossberg was super-healthy and picked at 14 potential degrees on our last day of picking [2 October].’

Low acidity

CIVA has allowed acidification in Alsace for the first time since 2003, ‘because acidities were lower than in previous years’. But, acidity is above 2003 in general thanks to cool evenings in August and September.

Botrytis scarce

Dry and sunny weather means little botrytis, especially for Gewurtztraminer. U p to 20mm of rain in early October prompted some botrytis for the thinner-skinned Riesling grapes. CIVA spokesman Guillaume Arnold said that many vintners would make sweet late harvest wines based on passerillage (drying out grapes to enhance concentration) rather than on botrytis.