Peter Boonen runs the Catharinadal farm in Hamont-Achel, Limburg province, where he makes the cheese with his brother, Bert, together with their wives. The brothers took over from their father, who still works on the farm, and who was more of a butter producer in his day. The farm produces 140 different cheeses, as well as 70 or so other dairy products.

"I made my first cheese when I was 13," says Boonen. "That's 30 years ago now." He made his first blue cheese more than 20 years ago, "but I never expected to win any prizes."

Boonen himself couldn't be present in Lyon, where the prize was awarded a few weeks ago. "I should have been there, but in the end I couldn't go. But it feels great. It's a real vindication of everything we've done here."

The Achelse Blauwe, or Grevenbroecker to give it its Sunday name, is a deeply veined blue cheese with a most particular appearance, which looks like marble when it's cut. "It dresses up any cheeseboard," Boonen says. "A lot of people don't like blue cheese because they find it too pikant. It has a sort of dulling effect on the tongue, as if your tongue has been anaesthetised."

But the Achelse Blauwe doesn't produce that effect. "It has the full depth of taste of a blue cheese, but it's milder," explains Boonen. It's also low in salt and spreads at room temperature.

The apotheosis of the Achelse Blauwe came about not by accident but because of the great bogey-man of all farmers: EU regulations. The Boonens were told by inspectors from the Federal Food Safety Agency that they would have to renovate their cheese workshop to meet hygiene regulations.

"Renovations like that cost a lot of money," Boonen says. "Up until then we had been selling the cheese to people in town, but to make more money we decided to go outside the borders of the commune. I suppose that's what eventually brought us to the attention of people outside."

The effect was immediate. Last year he took part in a competition against 15 or so other producers, and the cheese's performance there assured it of a place representing Belgium at the Caseus Awards in Lyon at the end of January. The awards as a whole were won by France, but in one of the sections, where the 12 participating countries present an original cheese, Boonen's blue won with an impressive 18.3 points out of a total 20.

It's not likely success will go to Boonen's head. "I can barely make 16 cheeses a week," he says. "It's very labour intensive. Other blue cheeses use the technique of piercing the cheese with holes to let the air in." This carries the bacteria that create the mould that shows up as blue veins. The Achelse Blauwe is instead made of layers of stacked curds.

"We let it remain open to the air for six to eight weeks, until the mould is created and the cheese becomes soft, and then we close it up," explains Boonen. "Then I have to clean and disinfect the whole workshop here - everything from top to bottom - before I'm allowed to go on making all the other cheeses we produce."

I suggest he might find himself in the same position as the monks from the abbey of Westvleteren, who every year have to cope with a tsunami of beer lovers desperate to get their hands on some of the rigidly controlled, limited quantity of Westvleteren beer.

"I'm sure demand will increase," he admits. "We've already had enquiries about wholesale. But there's no way we could keep up if it goes further. Production will always be limited. We haven't even started rebuilding. The plans have only just been approved, and the work itself has maybe another year to go."

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