In the village of Maligny in the valley of the Serein river at the heart of chablis country, Jean-François Bordet surveys the vineyards his family has owned since 1590.

Spring, when the vines sprout their first leaves, is an uncertain time, when late frosts threaten to kill off early growth. Like other vignerons in this region of Burgundy, Bordet has been working day and night to protect his plants, a number of which are more than 100 years old.

In the last four years, chablis wine producers have had only one full grape harvest, in 2018. In 2016, the vines were damaged by hail, in 2017 by frost, and last year by frost and drought.

Bordet, a man who admits he sees the glass as half full, says he and his fellow vine growers had high hopes for 2020. That was before the coronavirus struck.

Today, the weather is just one of their worries. With bars, restaurants and brasseries closed in France and the UK – his biggest market – because of the lockdown, Burgundy winemakers are facing another bad year. The pallets in Bordet’s warehouse are stacked up and marked for delivery to the UK, but new orders have dried up.

“We’re still working and paying staff but at the same time we’re selling nothing,” Bordet says. “Not knowing if and when sales will pick up is psychologically very difficult.”

Facebook Twitter Pinterest Jean-François Bordet, chablis winemaker. Photograph: Kim Willsher

Bordet has 20 hectares (50 acres) of vines on the sloping right bank of the Serein facing a perfect south/south-east, from which he produces about 130,000 bottles a year.

This is the historical site of the birth of chablis. The soil, rich from the Kimmeridgian (late Jurassic) period 80m years ago, is made of white clay, limestone and fossilised oysters from a time the area was sea, giving chablis – 100% made from chardonnay grapes – its unique flavour.

Chablis is classified under four Appellation d’origine contrôlée (AOC) designations, the system of French certification: grand cru and premier cru at the top, followed by chablis and petit chablis.

Bordet, who produces six different chablis from his vineyards, including a grand cru and two premiers crus, has spent the last few nights soaking his vines with cold water to protect them from the frost.

The water produces heat as it freezes over the sprouting leaves and keeps them at zero so that they are not damaged by the frost, he explains. “It’s hard work, but we have to keep going. Nature isn’t stopped by the coronavirus.

“We can hope there will be a big party when the lockdown is over and business will pick up. Right now we can do nothing except look after our vines.”

The grower’s Domaine Séguinot Bordet label sells 6-7m bottles of chablis to the UK each year – roughly a third of its sales. This year, the salons and tastings that produce orders have all been cancelled, as well as an important dégustation next month in London hosted by 40 chablis winemakers.

The entrance to the village of Chablis, on the shortlist for this year’s prettiest place in France title, is marked by a large sculpture of a hand holding a bunch of unnaturally golden grapes.

Through the village, the road to Maligny is a gently rolling landscape dotted with parallel lines of stumpy vines where frowning, weathered vignerons are inspecting plants for growth and damage, ploughing out weeds and repairing trellises.

Bordet, 45, president of the chablis committee of the BIVB (the Bourgogne wine board), remembers walking the family’s vineyards with his grandfather when he was five, and the huge village dinner and parties when the harvest was brought in, picked by hand in those days, rather than mechanically as it is now.

“I miss that time of fête after the harvest. There was a meal, games, dances – it was very festive. But it would take 50-70 people to pick the grapes by hand and already there’s a shortage of people to work,” he says.

Chablis winemakers now struggle to find workers, he said. “We need around 300-400 people, but youngsters nowadays don’t want to do this kind of work. It is hard, you are outside in all weather, rain, cold and shine. But at least you’re out in the country, in nature.

“In France we have scorned manual jobs for too long, but doing a job like this doesn’t mean you’re not intelligent.”

Alberic Bichot is the sixth generation to work the family domaines, which produce internationally recognised burgundy wines mostly in Beaune, to the south of Chablis, where he also has a vineyard. He says the region’s winemakers have built up less stock than their Bordeaux cousins, for whom this year will be a “catastrophe”.

He says, however, that with “Brexit, Donald Trump’s threat to impose a 25% import tax on French wine and now the virus … we will suffer”.

Bichot added: “Some of the big UK supermarkets are still ordering wine, but with all the restaurants, hotels and bars closed, the orders are drying up.

“There are worrying times ahead. But we Bourguignons are lucky in that we can keep our spirits up looking after the vines in the hope that everything will one day return to normal. At least we are outside, not cooped up in a small apartment or producing something that will rot if not sold.”

For the winemakers, however, even hard work brings no guarantees, says Bordet. “Nothing is certain; as we have seen in recent years, sometimes it’s too hot, sometimes too cold, or there’s too much rain or too little rain, or frost and hail … But we’re optimists. We have to be.”