A Tasmanian farmer's suggestion that people make champagne with their surplus rhubarb has drawn a legal warning from the French.

Key points: Days after suggesting that his Facebook followers should make rhubarb champagne, Guy Robertson got a call from a French official

Days after suggesting that his Facebook followers should make rhubarb champagne, Guy Robertson got a call from a French official Mr Robertson thought it was funny, and said the official was a nice guy but took it seriously

Mr Robertson thought it was funny, and said the official was a nice guy but took it seriously Under international law, only champagne from the Champagne region in France is allowed to trade using the term

Guy Robertson from Penguin-based Mount Gnomon Farm suggested on social media that those with surplus rhubarb could treat themselves, as he had, by brewing some homemade rhubarb bubbly, which he termed champagne.

A couple of days later he received a phone call from a French official in relation to the post.

"He was a really nice guy, he said: 'I know it's a really bad time around the world at the moment, but our legal team takes it very seriously'," Mr Robertson told Helen Shield on ABC Radio Hobart.

"He said he has been doing it for three years and it's his job to make sure everyone complies and nobody markets their bubbles as champagne unless you come from the Champagne region in France.

"It was a funny moment for me, I just couldn't believe I had a call from France in the current climate about 10 litres of home-brew that we aren't even marketing."

A crop of rhubarb at Mount Gnomon Farm. ( Supplied: Mount Gnomon Farm )

Organisations such as the Comité Champagne protect and promote the Champagne brand.

Mr Robertson said the official had received a complaint about his social media post and had to follow it up, but managed to see the funny side of it.

"They take their job very seriously," Mr Robertson said.

"It made me laugh and laugh.

"If I ever go into the production of rhubarb champagne, I'll have to call it something different."

Mr Robertson says as well as stewed or in a crumble, rhubarb can be made into cordial or sparkling wine. ( Supplied: Mount Gnomon Farm )

From paddock to plate via the web

Mount Gnomon Farm sells produce at farmers' markets and festivals, hosts on-farm experiences, and supplies restaurants.

The COVID-19 crisis has resulted in the business losing almost 100 per cent of its revenue overnight.

"When we found out we wouldn't be able to attend Dark Mofo the dominoes started to fall," he said.

In early March, Tasmania's largest festival Dark Mofo announced it would not go ahead due to the virus outbreak.

"The first week was the sleepless week," Mr Robertson said.

"Then we realised we could put everything online."

Mr Robertson said he had created a website for his business and was now incredibly busy selling meat, vegetables, and fruit online, as well as the products of other local artisan producers.

Since going online, he has sold 1,000 products and is delivering food boxes all around the state.

"The most encouraging thing is the community support," he said.

"We're trying to focus on what we can do rather than what we can't do."

For Easter, he has 70 deliveries around the North West, 50 to Launceston and 60 to Hobart — all being driven himself.

And rhubarb is making an appearance in all the produce boxes.