Dramatically fluctuating weather puts Belgium’s wine at risk

The dramatic swing from last week’s heatwave weather to the snowfall of the last few days has caused concern among many in agricultural circles, specifically those who run vineyards, as well as fruit growers and asparagus farmers. The big question is what impact the rapidly fluctuating temperatures will have on their harvests.

Bertrand Hautier, owner of the Domaine du Chapter in Nivelles, which produces about 50,000 bottles of wine a year, usually protects his vines with heat blowers on cold evenings but recent nights have proved more problematic. "It was cold but there was also a lot of wind, so the heaters were not of much use,” he said.

“Who knows what happens tomorrow? Maybe there are colder temperatures but less wind, so we can act. Our blowers are usually used during the frosty nights in April and May. These are frosty nights when there is not much wind, where there are no clouds and so it is more cold areas that are created. There is then a way to warm the air, either with wind turbines or with heat blowers, but here, as it is cold coming from the north with a lot of wind and icy air, everything is in flux. We don't know what to do except look and hope it doesn't freeze."

What the winemaker fears more than the snow, which plays an insulating role, is a frost. "The snow can be positive, but it still has to stay on the buds, and it has to cover them all night," Hautier said.

The impact of a frost depends on the stage of the buds’ development. "If they are green then the buds can explode with frost,” said Hautier. “The frost crystals are going to blow up the buds and destroy them. And since most of the clusters are on these first buds, you can lose a large part of the crop if those buds die."

Fewer buds not only mean less wine, but sometimes also less quality. "For example, for chardonnay, if the first buds freeze, it will not bear fruit at all over the year, so it's the total loss of the harvest. There are other varieties that make grapes, but you still lose almost a month on the harvest date. So, it will create less quality, or it will lead to more sparkling because we will not reach the same maturity."