Mark Porter visits a Napoleonic fort that stands guard over millions of pounds worth of fine French cheese.
Deep in the bowels of a huge alpine fortress, across a vast valley from the crystalline silhouette of Mont Blanc, a former French commando is listening to cheese. In his hand he carries a gouge, and periodically he seizes a large, yellow wheel of mould-encrusted curd and taps it with the gouge's wooden handle. There is a dull thud followed by complete silence as the cheese master sits in judgement.
"Il est bon," pronounces Jean-Charles Arnaud. The wheel is neither too holed nor too cracked; it is 40kg of fermented cow's milk heading towards maturity. He skewers a sliver, rolls it between finger and thumb, sniffs, tastes and cogitates. In three months, he reckons, the balance of flavour and texture of this Comté cheese will be perfect - deliciously nutty and firm.
I am pleased to hear this because it means we can get back to the daylight. Down here the cold air is ammonia-laden, 95 per cent humid and utterly stifling. The floor is an inch deep in water, and icy perspiration trickles down the limestone walls. Perched among the 40,000 wheels in the miles of tunnelling, even the statuette of St Uguzon, patron saint of French cheesemakers, looks clammy and uncomfortable.
Jean-Charles is the boss of Fromageries Arnaud, which produces one of the finest Comté cheeses. His family business spans back to the turn of the last century, but has expanded since he bought this Napoleonic pile 30km over the French border north of Geneva.
Fort des Rousses is the second biggest fort in France, and is where 45-year-old M. Arnaud was based when he was chief climbing instructor of the 23rd Fontenoy Mountain Assault Regiment. He liked it so much that, when President Chirac did away with national service and sold the country's military bases, he acquired it.
"For the maturing of Comté cheese it is ideal. There's 80,000 cubic metres of storage space and the temperature is a constant 8°C, even if it's minus or plus 30°C on the ground. The passages were built to allow 3,500 men and 1,500 horses to survive for a year in the event of invasion, and there's also a river down there."
Having taken 1,500 stonemasons several decades to build, it must be the world's most impressive cheese vault - a veritable Fort Knox protecting produce with a street value of more than £60 million.
Maturing the Arnaud cheese takes up to 15 months. Some may, in fact, take less than a year, but to stay top of the Comté pile, it is important for the affineurs (maturers) to get it just right. All Comté cheese is independently checked since it is one of very few types to command an Appellation d'Origine Contr�lée label, more commonly associated with wine. To qualify as aoc, a Comté cheese must score 12 out of 20 from a panel of markers. Arnaud products tend to reach around the 18 mark.
After a morning at Fort Rousses, we drive north into deepest Haut Jura, to check out the other end of the grass-to-riches story. Here in the lush rolling valleys of the Franche-Comté region, herds of Montbeliarde cows munch all day before waddling back to the milking pens. Each cow must have a hectare (nearly 2.5 acres) of space. It must eat only fresh grass, or hay in the winter. This makes for milk of the highest quality.
Some local farmers have just 30 cows. This is barely enough to make one cheese a day. However they also own between them the fruitières where the raw milk is brought every morning to be turned into great slabs of curd. There are nearly 200 fruitières in the region, and they in turn sell on to the affineurs like M. Arnaud, and afterwards split the proceeds between the farmers.
Daniel Villet is the maître fromagier from the village of Doye. Every day he starts collecting milk at 5.30am. He visits eight farms and gathers 4,000 litres of foaming raw produce - enough to make around ten cheeses.
M. Villet partially skims the milk then pours it into a huge copper kettle, where it is heated to 33°C. He then adds rennet, which curdles the contents within half an hour. With a pair of paddles that resemble large toast racks, the contents are cut into pieces the size of a fingernail. Then they are heated slowly to 54°C for about 40 minutes.
By this stage it's like a sauna at the fruitière, but M. Villet's daily routine keeps him so fit that he hasn't even broken into a sweat. It's a relief for me, however, when the heaters come off and the straining begins. Once this has been done, the wheels are ready for the pre-maturing cellars.
The fruitières, by dint of law, must be used 365 days a year because of the raw milk content. If left for so much as a day, the Devil's own bacteria could lay waste to much of France, and only the constant usage and heat keeps it at bay (any form of sterilisation is strictly interdit.)
The result of this painstaking process is the richest and most popular cheese in France. More than 40 per cent of the population eat it and total annual production is some 38,000 tonnes. But what of the end taste? Well, to start with there's butter, cream, dark chocolate, grilled bread, nuts, apricots, prunes, onions, honey and leather. There are then, we are assured by cheese aficionados, a further 73 different flavours.
All of which shows how wrong de Gaulle was when he asked: "How can you govern a country which has 246 varieties of cheese?" France is much more complicated than that: there are more than 500, and if they all have 83 different flavours, there is no hope left. Least of all for St Uguzon, who was put to death for feeding crumbs of the nation's biggest business to the poor.