In late July, the mercury hit its highest level since temperature records began on the Moselle. Vineyards suffered significant damage as a result of these conditions. These climatic disruptions came in the wake of a late frost in May.
When temperatures rise to 42°C in vineyards in Spain, Italy or the Languedoc region of France, it is not good news. However, the grape varieties planted in these regions are well-suited to a hot, dry climate. In contrast, miracles could not be expected in Luxembourg with its varieties suited to a more temperate climate. Jean Cao, a consultant oenologist to independent wine-growers who studied wine-growing and wine-making at the University of Montpellier was under no illusions: “even southern European vineyards are unable to withstand these conditions, so here…”
Vines benefit from sun, adapting well to barren soil and water shortages. However, there are limits to their resilience and these were reached. “The best-oriented (i.e. south-facing) parcels suffered the most between 4 and 6 pm when temperatures are at their highest,” explains Jean-Paul Krier (Krier-Bisenius estate in Bech-Kleinmacher). So, paradoxically the best slopes paid the highest price.
“Temperatures were verging on 50°C at the foot of terrace walls or cliffs due to reflected heat,” observes Marc Desom (Desom cellars and estate in Remich). Armand Schmit (Schmit-Folh estate in Ahn), a qualified geographer, puts the event in context: “42°C is extremely high! Not so long ago, such temperatures were only seen in the Sahel and they seemed unbearable to us… Now it’s like that in our country.”
No winegrowers in living memory have experienced this. Armand Schmit continues: “I said to Ern (editor’s note: Ern Schumacher, a wine-grower on the Schumacher-Lehal estate in Wormeldange and chairman of the independent winegrowers) that if we told our fathers who passed away around 20 years ago that we’d lost grapes due to temperatures of 42°C in the vineyards, they would say ‘what have you been doing since we left?’”
This year, the success of the harvest has been dependent on the efforts of the wine-growers
In fact, the heatwave caused the grapes to dry out prematurely. Like unripe raisins, the berries took the full force of the sun’s rays and dried out. Some clusters of grapes died, while others were only partially affected. This is a tricky situation, since spoiled grapes would ruin an entire vat if they were brought to press. Special care is needed, particularly when making red wines, which require maceration and prolonged contact between the must and the grapes. “Fermentation must be kept as short as possible, lasting no more than 36 or 48 hours,” confirms Jean-Marie Vesque (Cep d’Or estate in Hëttermillen). “My estate will produce less red wine this year.”
This nevertheless does not mean that no good wines will be produced. “This year, the success of the harvest has been dependent on the efforts of the wine-growers,” smiles Yves Sunnen (Sunnen-Hoffmann estate in Remerschen) as a lot of work has been required to achieve a good harvest.”