The almost cult-like fascination with a brooding bear of a red wine called petite sirah is one of the greatest under-the-radar wine stories of the last decade.

First conceived as a varietal wine in 1964 by Concannon Vineyards in Livermore, the variety took roughly three sleepy decades before it decided it was time to put on a show.

In the last few years, however, demand for petite sirah has shot out of sight. Where just six years ago, prices for top-rate petite sirah grapes were well under $1,000 per ton, today, in the best regions, petite sirah is fetching three times that, rivaling prestigious cabernet sauvignon in some regions.

The reason for this surge in interest starts more with producers than consumers. Wine makers, looking for a grape that can make a chunky, powerhouse red wine that works superbly with roast beast, discovered that petite sirah has only one downside. More about that later.

So, they started making small amounts of the wine, many of them from purchased grapes. In 2000, the number of petite sirah producers in California was estimated at about 60. Today, a trade group that promotes the grape said a count showed 282 producers of the wine.

"It's going nuts for me," said Jo Diaz, head of a group called P.S. I Love You, which promotes the wine. She admitted that most wineries that make it "are producing no more than 300 cases each, and many of them are just trying to see what they can do with it. But the demand is beginning to outstrip the supply right now."

The leading producer in the United States is Bogle Vineyards, which in 2005 hit 100,000 cases of the wine. Concannon and Sonoma County's Foppiano each make 60,000 cases a year.

Patty Bogle said the increased demand for the wine has shocked her. "We started out making chenin blanc and petite sirah, wines that weren't all that popular, and now look at what's happened with one of them!"

Fifty years ago, petite sirah was the most heavily planted grape in the Napa Valley. As cabernet sauvignon gained fame, many old petite sirah vineyards were torn out, but Bogle said that "a few rows (of petite sirah) were left in most vineyards, and some people are now planting more. It's always been our favorite red.

"Now it's really taking off. It's a grape that hasn't needed a movie, people just found it and liked it."

Today, such famed wine makers as Kent Rosenblum (Rosenblum Cellars), Helen Turley (Marcassin), Sean Thackery, Carl Doumani (Quixote and Panza), Stags' Leap Winery and Girard all make petite sirah.

The one drawback to this powerful red wine, mentioned above, is that it can be mighty astringent when young. The high tannins in the wine do, however, help it age nicely. I have a few 35-year-old bottlings in my cellar that are still in great shape. To drink a petite sirah young, decant it for at least an hour, and always serve with hearty foods.

Growers say they find petite sirah a challenge. The vine needs special treatment (mineral additions to the soil), and it is susceptible to eutypa, a sort of fungal disease that can kill it. Petite sirah growers and wine makers will gather for a technical conference in August to deal with such issues.

Meanwhile, consumers can look for any of the following exceptional examples of petite sirah, wines I tasted in mid-January and which impressed me greatly: 2002 Wilson Vineyards, Dry Creek Valley ($30); 2003 Mettler Family, Lodi ($25); 2002 Silkwood, Stanislaus County ($36); 2002 Lava Cap, Sierra Foothills ($30); 2003 Marr, Tehama Foothills ($27); 2003 Trentadue "La Storia" ($28), and 2003 Ledson, Contra Costa County ($34).

As Patty Bogle put it, "There is something magical about this wine."

Wine of the Week: 2003 David Bruce Petite Sirah, Central Coast ($20): Rich aroma of red currant fruit with a bit of leafy character. Relatively rich and astringent, but smoother than most of those above -- and it's a lot better with an hour of aeration in a decanter.

Dan Berger resides in Sonoma County. Berger publishes a weekly newsletter on wine and can be reached at danberger@VintageExperiences.com.