Jacques Reynaud, the late owner of Château Rayas, was notorious for playing tricks on journalists. A friend of mine once told me a story about turning up for a pre-arranged tasting to find the place deserted. He consulted his watch, stamped his feet, but half an hour later there was still no sign of Monsieur Reynaud. Eventually he gave up and got back into his car. As he was driving away, he glanced in his rear-view mirror and there, climbing out of a ditch, was the owner of the most famous property in Châteauneuf-du-Pape.

My own first meeting with the self-styled king of the Rhône was no less bizarre. He turned up on time, but when I asked if I could taste his wines, he smiled and handed me a grubby, fingerprint-smeared glass with no base. To take notes, I had to wedge the glass under my armpit: Château Rayas was literally impossible to put down.

I think I passed the test because, after the tasting, Monsieur Reynaud (never Jacques) took me into the vineyards to show me his wizened 80 year-old vines, each of which yields a tiny quality of dense, silky, highly alcoholic red wine. Châteauneuf-du-Pape is famous for being a blended wine (it can contain as many as 13 varieties), but in many vintages, Rayas is made entirely, or almost entirely , from Grenache. As such, it is the most famous example of this most hedonistic of grapes. Monsieur Reynaud may have gone, but his wine lives on.

Like a sun worshipper heading for the Côte d’Azur, Grenache likes to catch a few rays, and not only in Provence. The grape can be found in Australia, South Africa, California and Mexico, but to me it’s the quintessential southern European grape, blanketing huge expanses of Spain and the south of France. You can argue about the grape’s origins – the latest research suggests Spain, where Garnacha Tinta (as it’s known locally) is enjoying a revival worthy of Mary Berry – but Grenache belongs to the Mediterranean as a whole. There are plantings in Greece, Cyprus, Sardinia (where the grape is called Cannonau), Israel, Sicily and Morocco.

Grenache does not produce wines for the faint-hearted – the alcohol socks you between the eyes. To show at its best, it needs to ripen to at least 14 per cent (alcohol by volume); and in some cases it can hit 16 per cent or more. Grenache varies enormously in style, but pronounced alcohol is a common theme. So are softness, fleshiness and (when the wines are young) flavours of summer pudding. Mind you, the grape makes so many distinct types of wine that you could have a five-course meal and serve a different Grenache with each dish.

Grenache, believe it or not, is the most planted red grape in the world. And most of those plantings are found in Spain, where Garnacha used to be regarded as a grape that was fine only for blending or making rosés. In Rioja, it is still used to add warmth, alcohol and fruit to the more austere Tempranillo. The same is true in Navarra, although here a lot of Garnacha finds its way into the region’s excellent rosés (Chivite and Ochoa are good examples). Garnacha also pops up in Calatayud, Campo de Borja and Cariñena, producing everything from frivolous pinks to dense reds, sometimes in a blend, occasionally as a solo performer.

However, the region where Garnacha gets headline billing is Priorat, a tiny region to the south of Barcelona. The grape has been grown here for centuries, but it has become ultra-fashionable in the past decade. It is sometimes blended with Bordeaux varieties, such as Cabernet Sauvignon and Merlot, but it is Garnacha that gives the area’s best wines their heady flavours and supply texture. The producers to look out for are Alvaro Palacios, Clos Erasmus, Clos Mogador, Clos Martinet and Costers del Siruana. But be warned: the wines are pricey. For a cheaper alternative, try the wines from Celler de Capçanes in nearby Montsant.

High prices have started to affect Châteauneuf-du-Pape, Grenache’s French home from home, especially after a good run of vintages in 2000, 2005, 2007 and 2010. The top wines are just as expensive as those from Priorat. Cuvée Justine from Domaine du Pegau, for instance, now fetches over £200 a bottle. The good news is that basic Châteauneuf-du-Pape is the famous name in these parts, but you can find wonderful and invariably cheaper Grenache-based wines in nearby appellations, such as Tavel (for rosé), Gigondas, Vacqueyras, Cairanne and Côtes du Rhône Villages.

In a totally different style, try a bottle of Maury or Banyuls, fortified wines made from Grenache in the Roussillon region near France’s border with Spain. These wines are softer and less tannic than Port, but at their best, they can be just as complex. Mas Amiel, Cazes, Domaine de la Tour Vieille, Domaine de la Rectorie and the Maury co-operative are all excellent producers. There are also producers making unfortified styles, most notably Domaine Jones. 

Outside the Mediterranean, Grenache has adapted well to the warmer regions of Australia (the Barossa Valley and McLaren Vale) and California (the Central Valley). The Aussies take the grape more seriously than the Californians and, with the exception of Bonny Doon’s Clos de Gilroy and Alban’s Grenache, it shows. Full-throttle examples are produced by Tim Adams (The Fergus), Rockford, d’Arenberg (The Custodian), Hardy’s, Clarendon Hills, Tatachilla and Charles Melton. Grenache is also blended with other grapes, most notably Shiraz, Down Under. My favourite Aussie blend is Charles Melton’s Nine Popes, a mistranslation of Châteauneuf-du-Pape. ‘Someone told me there were nine Avignon Popes,’ Melton explains with a smile, ‘but by the time I found out the truth, it was too late.’ I don’t think the two men ever met, but given his sense of humour, I reckon the joke would have appealed to Jacques Reynaud.

Crib sheet

• SMELLS AND TASTES OF: fruit, mint, cloves and olives when young; leather, figs, almonds, tobacco and spice with age. Fortified examples can taste like tawny or vintage port. 
•  GOES WITH: anything from salads to desserts. It will partner robust fish dishes as well as the more obvious lamb, venison and beef. Châteauneuf-du-Pape is the ideal casserole-friendly red. Maury and Banyuls are superb with dark chocolate. 
• COSTS: £3.99 for basic Côtes du Rhône, up to £200 or more for a top Priorat or an older vintage of Château Rayas. 
•  DO SAY: ‘It is the world’s most planted red variety.’ 
•  DON’T SAY: ‘Are Cannonau and Grenache the same thing?’