Loire: Frost and Frost Protection

Over the last decade spring frosts in the Loire, especially in April, have unfortunately become so common that #f***legel is now a hashtag (le gel being the ice).

Because of the northerly latitude of the Loire, frosts in spring have always been a concern – when they strike, they can have serious consequences. The night of 21st/22nd April 1991 has an especially black place in the Loire’s history when, after rain on the 21st, the skies cleared and temperatures dropped to as low as –6˚C. Bud break had been early, with growth already well advanced, so in the bright, early morning sunshine that followed, the tender young buds and vine shoots were burnt. The damage was widespread. Production that year was a third of normal.

Over the last decade, the frequency of spring frosts has increased, with serious damage occuring in 2012, 2016, 2017 and 2019, as well as some in 2013.

Sancerre has been lucky, it has been spared any significant loss. This luck has been due to the appellation’s topography, which sees many of the vines planted on steep slopes that allow the cold air to drain down away from the vines. In contrast, neighbouring Pouilly-Fumé has slopes that are overall much more gentle: it has been hit by frost several times, most severely in 2016.

The frost of 4th April 2019 followed the same lethal pattern as 1991: rain on the 3rd ensured plenty of moisture for the formation of ice during the freezing night; then bright sun in the early morning did the damage. This is often the way: the ice around the delicate buds acts as a magnifying glass so that sunshine can then burn the buds and shoots.

Following the severe frosts of spring 2016, there has been considerable investment in a variety of frost protection measures. This has included installing wind machines, which disperse the cold air, and aspersion systems (to spray water on the vines before the temperature drops too low, thus forming a protective layer of ice that shields the buds from heavier frost), hiring helicopters (the rotors push warmer air down towards the plant canopy), using frost pots to warm the air around the vines and – in a similar but more basic technique – setting fire to bales of straw.

Unfortunately, providing protection against frost is complicated, especially in regions like the Loire where land ownership is divided into small parcels of vines, often widely scattered. Here, it is essential for producers to cooperate and work together, which sadly does not always happen. And frost can be unpredictable – sometimes hitting vineyards that are normally frost-free.

Chinon has made substantial investments in wind machines as well as weather stations to provide a warning of low temperatures. As a result of these measures, a considerable part of the vineyard at risk is now protected. There has been similar cooperation to provide wind machines in Saint-Nicolas-de-Bourgueil. In contrast there is little cooperation in Savennières. Modern wind machines cost in the region of £55,000 each. These days they do start automatically, unlike the older ones that needed the producer to get up in the middle of the night!

Helicopters are expensive to hire and their noise is likely to provoke complaints in urban areas. They may also be banned from flying as Jérôme Choblet (Domaine des Herbauges, Muscadet Côtes de Grandlieu) discovered last year. ‘I hired three helicopters but they couldn’t fly as I am too close to Nantes Airport!’, he explained.

Aspersion, a system used widely in Chablis, is an option but is expensive and problematic in years of low rainfall.

There are no easy answers, but the battle is on. Unfortunately, for a number of producers, like Philippe Socheleau (Domaine des Deux Vallées, Anjou), keeping their fingers firmly crossed is still their sole protection!