RIVER DEEP, VINEYARDS HIGH

You can't walk down the street without coming across authenticity these days. So much so that Darius Sanai decided to embark on a journey through Europe in search of the authentic, authentic.

Authenticity is everywhere these days. You can't walk down a luxury shopping street without it bursting out at you: brands celebrating their history, whether it's Louis Vuitton telling the story of the original travelling craftsman Monsieur Vuitton, or Ermenegildo Zegna talking about more than 100 years of making cloth in its home town of Trivero. Sometimes the authenticity is untold: Chateau Lafite doesn't boast openly that its wine has been collected by the world's aristocrats since Thomas Jefferson toured France in the 1780s, but it is implicit. In a world awash with new money, old brands are king.

In some cases, like those above, authenticity is effortless, part of what gives the brand its fuel in the 21st century. Probably 99 per cent of purchasers of a Birkin bag couldn't tell you that Thierry Hermes set up shop as a leather saddle maker in Paris in 1837, but the knowledge is there, somewhere deep within the brand, part of its DNA.

In others, the authenticity is a little more contrived: you can see evidence of scrambling through archives, and of confused messages: is this a fashion brand or a luxury goods brand or...? You can't be authentic without having a halo product you are authentically the world leader at. Still none of the brands above, world leaders though they are, can claim to have invented their products. Trunks, cloth and saddles all existed before Messrs Vuitton, Zegna and Hermes perfected their art. To be able to claim this ultimate certificate of authenticity, to have invented the entire product category you specialise in, is the brand calling card ne plus ultra. Mercedes-Benz is celebrating doing exactly that, with this year the 125th anniversary of the first patent taken out on the first motor car by Carl Benz, near Stuttgart, in 1886. Such a boast is worth exploring further, and while Germany is hosting a whole series of events this autumn to celebrate, I thought the best way to do so was a private pilgrimage to the factory, rather like visiting the artisans of Hermes in Paris, or the watchmakers of Patek Philippe in Geneva, followed by a luxurious tour of Germany in one of their new products.

Arrive at the factory in the Stuttgart suburb of Sindelfingen and the first thing that strikes you is the air of slick efficiency. There's not a machine to be heard in the reception area, which instea d resembl es o ne of the pleasanter airline lounges, with a bank of uniformed blondes welcoming you to the right, and an even more arresting sight on display to the left. What at first looks like a large toy transpires, on closer inspection, to be the first car: the motorised carriage which Karl Benz took out his patent on, 125 years ago.

Ingenious and fragile looking today, the script beside the exhibit explains that while the car was invented by a man, it probably would not have been recognised had it not been for a woman, Karl's wife Bertha, who wanted to publicise the shy Karl's contraption sitting in its garage, and took it for its first public ride (uninsured, with no access to petrol stations as they hadn't been invented yet, and without her husband's permission - making it the first joyride as well). The crowds that gathered around ensured the word spread, and, 125 years later, there is a patient gathering of well-off people from across Europe waiting here with cups of coffee and slices of apple strudel, here to collect their own new cars from the factory.

First, through the tour, and after being shown a maquette of the factory complex, which is as large and populous as a small town and boasts its own racetrack, we are walked into an adjoining building, where yellow robots the size of small houses grab and piece together parts of E-class saloons as they shuffle down long lines. Workers overseeing the process cycle from one end of the factory to the other as the cars take shape before us.

In between buildings (the different stages of production are housed in different units) we catch sight of a couple of cars tearing down the test track, and of an as-yet unreleased SLS convertible supercar sitting outside awaiting its own testing.

Tour over, we sit in a gallery overlooking a cavernous, carpeted hangar where every few minutes a newly minted Mercedes rolls in through a set of giant doors connecting it to the factory preparation area, to be joined by (usually) a beaming family who are introduced to the car by one of the technicians who helped build it.

After a few minutes my name was called out as a pearl white CLS, an elongated, four-door coupe, rolled into the hangar. The technician greeted me and showed me around the car, which looked languidly luxurious with an interior of 'ebony and ivory' (cream seats and leather inlays, piano black wood around the dash). The new CLS, the second generation of a model that claimed to have invented the 'four door coupe' category, has the option of a new V6 turbo diesel engine that produces enough power to catapult you down the road as fast as my old bachelor Porsches, and yet is cleaner than a Volkswagen Golf of a couple of years ago.

It was with this engine humming quietly in front of me that I steered out of the factory and on to the adjoining autobahn. Speaking of steering, the car has a new electrichydraulic steering system that is supposed to provide the efficiency of electrically-powered steering with the feedback of the old kind. Its weighting felt meaty, satisfying, unlike the computer-game lightness of some luxury cars' steering systems (including, it should be said, until recently Mercedes' own top-of-the-line CL.)

In heavily trafficked roads, plenty of mid-range power is what you need to surge you forward without effort, and that's exactly what I found in the new engine, which felt to drive like an old-fashioned V8 petrol engine (that's a compliment, as I love the languid punch of a V8) but with the drinking habits of a frugal economy car.

I was heading north west, through the forests and hills of central Germany, past Frankfurt and the ancient city of Worms (I was tempted to drop in but the arrival of a rainstorm dissuaded me). At Koblenz, just before a vast motorway bridge crossed a river, I turned off and turned westwards, into a landscape of dreams.

Germany has always played home to a sylvan, Arcadian myth: this is the land of the Erl King, of forest spirits. Despite (or perhaps because of?) its advanced industrialisation, the rural ideal always seems to hang above the national psyche. Just five minutes into the Mosel valley, on an empty, winding, S-shaped riverside road, and I had an inkling of why. The motorway and developments of the Rhine valley behind me had disappeared, replaced by two perfectly-proportioned valley sides in a sloping U, each thick with an alternation of vines and forest. The valley floor had just the perfect width of meadow and field (vines, again), before giving way (after the road) to a cycle trail and then a meandering river, as wide as a football pitch.

Eagles and hawks circled overhead; farm buildings and hamlets were made of Hansel and Gretel wood, and the occasional inn tempted with ministrations of local trout and white wine. The effect of the valley sides, no more than a couple of hundred metres high, served to seal the idyll from the rest of the world.

And it went on. Around a series of long, gentle esses we went - nothing too tight or claustrophobic, always a perfect, smooth surface for the CLS to glide along. Each time the vista revealed was a gentle continuation of before; the feared large town or industrial plant never materialised, even after an hour of guiding the new car.

I had come to the Mosel because I wanted to see it and taste its famed wines, which are among the world's finest, in their home area; and also because it serves as a sort of counterexample of branding. Mercedes-Benz is the ubersuccess story of how to turn a clever invention into a worldleading luxury brand despite ever-increasing competition: I would happily wager that the world's privileged will be driving, or driven in, S class saloons powered by whatever means applies, in 100 years time.

The Mosel valley is also the original home to a German world-beater: riesling, considered by most wine writers to be the greatest of all white wine grapes, capable of making wines of wondrous complexity. And yet Mosel riesling (and German riesling in general) has a wretched brand image. Exports are stuttering, prices languish far below those commanded by even mediocre white wines from France and California, and 'I've brought you some Mosel Riesling' is not something you are likely to hear from a caring friend anytime soon, unless you are a member of the small band of true wine buffs.

Despite its accolades from the world's wine experts - names like Urziger Wurzgarten and Wehlener Sonnenuhr will light up their souls as much as mentions of Montrachet or Corton - Mosel riesling is even unloved in its own country. Numerous German sommeliers have told me they sell an Aussie chardonnay much more easily, even to soi-disant connoisseurs. And in the ultimate indignity, the Federal government is soon to drive a six-lane motorway bridge through the heart of Mosel wine country, directly above some of the most fabled vineyards, destroying them forever. (It's unimaginable that even the autoroute-obsessed French authorities would do that to the Cote de Nuits).

As an example of a brand that has everything - history, quality, uniqueness, authenticity - Mosel riesling has everything, except the brand. I was intrigued to find out more. My first overnight stop came an hour or so into the interlinked esses of Arcadia. I turned right, away from the river, up a narrow high street at the wine village of Cochem. The road followed a broad valley cut into the hillside, and after a mile there was a sign for the Hotel Weissmuehle, pointing down a track in a cut in the hill. The cut was barely wide enough for the track and the stream that accompanied it; we were in a deep gorge, forest rising on either side, eagles circling in the narrow slit of sky visible above the valley sides.

At a clearing, at a point where the valley opened out into a meadow the size of a football field before ending abruptly in a rock face, was a trout pond, a terraced restaurant, and a country inn. The hotel, although relatively modern in construction, had the air of the kind of inn that has existed for centuries, perched on a favourable spot in the river, at the top of the secret valley.

The rooms in the Hotel Weissmuehle were probably no larger or more comfortable, save for the addition of ensuite bathrooms, than they had been in Goethe's time. We sat outside on the terrace, watching the eagles, ordered a bottle of riesling from the short list, and asked the chef to do his best. We received the most perfectly cooked trout, baked simply with a little butter, stuffed with handfuls of parsley from the forest. The flesh was gentle, buttery and firm, the parsley cooked just enough to ooze its oils into the trout, not so much that it appeared wilted. The sautéed forest mushrooms and potatoes were simple but again, so well judged that this unsophisticated meal for me outscored many more ambitious efforts in more celebrated hostelries.

And what of the wine? One of the challenges of Mosel riesling, of German wine in general, is the quasi-impenetrable labelling. A riesling can be slightly off dry, nearly sweet, or liquerishly sweet; indeed rieslings from the same vineyard, with almost identical labelling, could be any of these. A broad spectrum of ripeness and sweetness runs from Kabinett, for the least ripe, through Spatlese and Auslese, to Trockenbeerenauslese, the latter being one of the world's sweetest and most concentrated wines.

But these are only indications of sweetness. In reality a Kabinett can be sweeter than an Auslese. In a world which overwhelmingly prefers dry wines, it's a marketing disaster in itself not to have any easy categorisation. Imagine if the makers of champagne, just 100 miles away in eastern France and among the world's canniest marketeers, made customers take part in a lottery as to whether their bottles would be Brut or the extremely out of fashion Demi Sec or Doux (semi sweet or sweet) styles?

I wanted to try a wine from just over the mountainside, from one of the Mosel's most celebrated vineyards, Erdener Treppchen, planted on an area of steep red slate with almost no topsoil. After a quick examination of the bottles available tracked one down with the key word on it: Trocken. Trocken, in a German white wine, generally means it's dry, unless it's a Trockenbeerenauslese, in which case it is intensely sweet. (I hope you're following. Can you imagine what would happen if the Germans marketed their cars like they do their wines? Oligarchs would all be in Lexuses.)

The Johann Josef Christoffel Erdener Treppchen Riesling Spatlese Trocken, Erste Lage, 2007, to give it its full, catchy title, that we had was beautifully tensed and balanced, bursting over the palate with a wave of tropical fruit (pears? bananas? limes?) which suggested intense sweetness to come, but then switched, halfway through the taste experience, to melt into a stony, mineral dryness. A brilliant wine, more interesting and challenging than many a celebrated white Burgundy.

The next day we carried on down the Mosel, along a series of gentle giant vineyard-clad esses, until we reached the town of Bernkastel, the main town of the Mosel. It still retains a genteel, backwaterish air, preserving the dream-like tranquility of the valley that we must assume will be shattered with the arrival of the motorway bridge, although this will be some miles up the river from Bernkastel itself. After strolling around the riverside and enjoying a grilled zander, or pike-perch, on the terrace of a restaurant in the old town square (washed down with some dry, bitter Kirner pils lager - wine isn't the only fine drink around here), we headed to our final destination, the Hotel Richtershof.

This is in a particularly scenic spot for wine lovers, on the south shore of the Mosel, facing a broad sweep of ribbed hillside that houses the Brauneberger Juffer vineyard, another of the Mosel's most celebrated. It was a warm evening, and we sat at a table in the ornamental garden of the hotel, and persuaded the staff to serve us dinner from the formal, and celebrated restaurant, out in the garden, over a tasting of dry rieslings from the Mosel's most celebrated vineyards. Brauneberger Juffer, Wehlener Sonnenuhr, Urziger Wurzgarten, Erdener Treppchen and Bernkastel Doktor were all represented - names that to a riesling connoisseur would mean the same as a tasting of Corton Charlemagne and Le Montrachet to a Burgundophile. The cuisine was ingenious, blending German tradition with the freshness of the garden that is the Mosel, with ingredients predominantly sourced locally. Knuckle of pork with crayfish and dandelion salad was a balance of meaty textured crustacean, gamey meat and bitter leaf. Chartreuse of (oversized) macaroni, scallop, tomato and watercress was a great match for the heft of the Urziger Wurzgarten riesling with its cascade of spices. Wild rabbit risotto with wild garlic from the local vineyards had a quasi-pornographic earthiness to it which brought out the best in the Brauneberger Juffer (we raised a glass to the vineyard on the opposite bank as we sipped). Picking a favourite, I opted for Wehlener Sonnenuhr as a vineyard for its blend of tension, mineral and richness.

A hotel on the Mosel is not anywhere on any young romantic's list of places to go for a weekend break - it has never been on mine - but as an experience for taste, smell, and sight, and for the mind, the cosy wilderness of the region is unique. For authenticity, it is unmatched.