Last week frost swept across some of the world’s most valuable vineyards, as Bordeaux, Champagne, and Burgundy experienced temperatures as low as –4°C (25ºF). The sub-zero temperatures hit hard between the hours of 5am and 7am on April 26 and 27. Winemakers rushed to protect the vines by lighting controlled fires and implementing heaters along and between the rows in the hope of keeping the frost at bay.

In a recent market update from Atlas Fine Wines, Stephan Derenoncourt, a consultant to many properties, commented on the damage in Bordeaux, which was particularly serious on the Right Bank: “There is damage everywhere, sometimes 100 percent.” Although the plateau in St-Emilion managed to elude serious harm, lower lying vineyards were much more vulnerable to the freeze, the extent of the damage still to be determined. Management at Château Lagrange suggested that, “This is the biggest frost in Bordeaux since the 1991 vintage.”

The warm spring conditions now turn out to have been more of a curse than a blessing, and young buds were killed by the freezing conditions. The frost won’t affect the potential quality of the wine, thankfully, but the overall yield will be substantially lower.

In some areas, particularly in the best vineyards, helicopters, in addition to the controlled fires, were used to prevent the frost.

English winemakers are also suffering. Prominent producers such as Nyetimber, Ridgeview, and Denbies Wine Estate, among others, have experienced “catastrophic damage” to buds, said Chris White, chief executive of Denbies Wine Estate in Surrey.

In Champagne, many winemakers are still determining the full extent of the damage, with the risk of more freezing conditions still to come. Gilles Descôtes, Bollinger’s chef de cave, commented: “At this time we expect to lose about 20 percent of the buds, but we are still working hard to ascertain just how extensive the damage is. The ‘Saints de Glace’ [Ice Saints] are 11th, 12th, 13th May, so we shall have to wait and see what they bring!”

Jean-Baptiste Lécaillon, chef de cave at Champagne Louis Roederer, said total production losses are expected to be 15 percent, and anticipates 25 percent of the 592 acres (240 ha) have been affected.

The 1945 and 1961 vintages also suffered heavy frost; nonetheless, the surviving grapes went on to become concentrated and perfectly ripe. There is the hope that the surviving vines will produce second buds, which should still produce good wines, even if yields will be lower.

The severe frost will affect not only the 2017 vintage, but the release prices of the 2016 wines, particularly the Bordeaux now being offered en primeur.