Night Harvesting in Marcillac: Preserving Grape Freshness and Quality in the Face of Global Warming

Better for the mechanics, better for the picker… and better for the rosé: in Marcillac (Gironde), the harvest takes place at night to preserve the freshness of the grapes, a practice which is spreading in the face of global warming. At five o’clock in the morning, while a late heat wave suffocates France in early September, it is around 20 degrees Celsius when the vines are traversed and shaken by the “vendangeuse”, a gantry tractor which straddles the ranks.

“Harvesting at night is for the quality of the grapes, for the freshness and the aromas”explains to AFP its driver, Loïc Malherbe, who has been up for two in the morning. “It’s not unpleasant, it’s a different rhythm of life. […] It’s better for the machine and better for the man too.” Better, too, for the energy bill in a Bordeaux vineyard in crisis, underlines Kees Van Leeuwen, professor of viticulture at Bordeaux Sciences Agro. This in fact makes it possible to avoid the costs of cooling the clusters.

“If we harvest at night, the temperature of the bunches is lower, especially on very hot days like this week. There is a huge advantage in the use of energy”, he argues. Once the vats are full of Merlot, the harvesting machine’s rotating beacon activates and Stéphane Héraud, the operator of the plot, positions his trailer to receive the grapes. “We’ve been picking whites and rosés at night for 15 years, and maybe one day we’ll also make the reds”observes the winegrower, president of the cooperative of the Vignerons de Tutiac. “If we harvested during the day, we would have more oxidized wines, so in terms of taste, it would be much less attractive.”

Stéphane Héraud climbs onto his trailer and sprinkles the harvest with dry ice (-80 degrees Celsius) taken from a cooler. Here too, it is a question of containing oxidation by reducing the quantity of oxygen in the skip, he specifies before driving seven tonnes of berries to the cellars of Tutiac, the first AOC cooperative in France with 500 winegrowers. members, 100 million euros in turnover and 190 employees.

Trailers and winegrowers parade among the dozens of stainless steel vats: some 500 tonnes of grapes must be brought to the press that night, the equivalent of 4,000 hectoliters of wine or 525,000 bottles. At the Vignerons de Tutiac, the focus on rosé (45,000 hectoliters produced per year, out of a total of 150,000 in Bordeaux) seems to be bearing fruit: one of the cuvées, labeled “Zero pesticide residue”, played spoilsport during a blind tasting of the Review of the wines of Franceranking fourth among the rosés of Provence, a reference in the category.

“To make good rosés, clear rosés as the consumer demands, color is a criterion“, recalls Paul Oui, chief oenologist of Tutiac. “We have to limit the migration of the color (of the skin) into the juice and for that, the earlier and fresher we pick the grapes, the more we manage to limit it.” The practice of night harvesting was already “common” in hot countries, such as Australia or California, but it is also tending to spread in Bordeaux, notes Kees Van Leeuwen.

“On whites and rosés, we can imagine that it will become generalized”, notes this academic who does not exclude that red, representing more than 85% of the Bordeaux vineyard, is also getting started because with climate change, the harvest is becoming increasingly early and therefore subject to high heat. This is confirmed by Stéphane Héraud: “I remember, when I was very young, seeing my parents harvest in November. Last year, on September 30, we had finished… Climate change, the one who says it doesn’t exist, he is not a winegrower in Bordeaux”.