If you want proof, there is no better way than to see for yourself. Champagne country is less than two hours from Paris by train, and most of the larger houses in Reims and Epernay have guided tours of the cellars.
Tours last around an hour, and cost between FF20 and FF50, depending on the house. The format varies little: a potted history of the region and its viticulture, the story of the house, a tour underground where the wine is stored and fermented. When you return to the surface, some houses offer a free glass of champagne.
If this sounds a little formulaic, it is. But there is a reason. The French are rightly proud of champagne, and the way it is made is tightly regulated. There are few differences between the houses' production methods, and so the tours do tend to cover the same ground.
The best way to pick a tour is to visit the house whose champagne you like best. If you don't have strong preference, then convenience - some tours have to be booked in advance - and location will be deciding factors. Reims is the more interesting town; Epernay has more public tours.
Of course, one of the best known grandes marques is Moet et Chandon, which has made champagne since 1743. The house is located on Epernay's avenue de Champagne. The headquarters are as opulent as you would expect - particularly when you bear in mind that Moet also owns the Dior perfume empire. We were shown round their impressive holdings by Kate, a well- spoken English guide who was knowledgeable and entertaining. English speaking tours take place as long as there are enough visitors; otherwise, there is the option of joining a French group.
Champagne cellars are damp and fascinating. Moet keeps its maturing stocks in 28km of tunnels below Epernay. Iron bars guard the Oenoteque, the "library". This houses the oldest bottles, with stocks dating back to Napoleon's time. Champagne was the emperor's preferred tipple. Napoleon was a loyal customer of Moet et Chandon, which is why, to this day, Moet calls its champagne Brut Imperial. According to our guide, Napoleon and his generals came to Epernay to fortify themselves before a campaign. The one time they did not was on the eve of Waterloo. They choose beer instead, an irony not lost on the French.
Wine for more immediate consumption is housed in a network of galleries. The longest gallery has 32 cellars, and the largest cellar holds 100,000 bottles. Moet alone has 92 million bottles of champagne in store. The labyrinth is so large that staff travel around by electric cart. One group does not: the remueur, or riddler. Riddlers are expert craftsmen who turn champagne bottles - by just a few degrees each day - to collect the sediment. The riddlers' craft is closely guarded; they, and only they, travel through the cellars by bicycle. Weekday visitors may catch the sight of a riddler at work, although only the Dom Perignon is now turned this way. The rest of Moet's production is riddled by machine.
Visiting more than one cellar is probably overkill for all but the most serious wine buffs, but the Champagne region is worth a longer stay. In the hills around Reims and Epernay are some cheerfully pretty villages. Chamery is particularly appealing. Here there is just one cafe, but every other farmhouse seems to sell champagne. Local producers charge around FF70 for non-vintage bottles, and visitors are welcome, even encouraged, to try before they buy.
If you want to stay overnight in the area, Reims offers rather more life than Epernay. Its champagne cellars are concentrated around the Place du General Gouraud, a square dominated by the Gothic splendour of Pommery's headquarters. Pommery offers tours of its cellars for FF30, including a degustation, but it recommends phoning first to book a place.
If you have to wait, the city has plenty to offer beyond its viticulture. Champagne is a relatively recent invention here. Dom Perignon may have started producing the wine in 1690, but most of Reims' champagne houses date from the 19th century. The cathedral, on the other hand, dates mostly from the 13th century, and Reims traces its origins back more than 2,000 years.
Pleasant squares, elegant shops, champagne flowing - Reims can hardly fail to please. Why, you can even order champagne in the city's one and only English pub.
Eurostar (0345 303030) trains from London Waterloo to Gare du Nord start at pounds 69 return. To qualify, travel on Tuesday to Thursday inclusive, in both directions, and stay for at least one Saturday night; or book 14 days ahead and travel there and back in a day, Monday to Thursday inclusive. The next lowest fare is pounds 89, about the same as a flight from a London airport.
One advantage of the train is that it is an easy 10-minute walk from the Gare du Nord to the Gare de l'Est. From here there are frequent trains to Reims and Epernay. Reims is running its first-ever Christmas fair, from 10 to 24 December.
Moet et Chandon (00 33 3 26 51 20 00); Pommery (00 33 3 26 61 62 56); Mercier (00 33 3 26 51 22 22). Epernay tourist information office (00 33 3 26 53 33 00); Reims tourist information office (00 33 3 26 77 45 25). French Government Tourist Office, 178 Piccadilly, London W1V 0AL (0891 244123).