Lately, there has been an increasing popularity of Bordeaux-style red wine blends, composed of varying proportions of Cabernet Sauvignon, Merlot, Cabernet Franc, Petit Verdot, Malbec and Carménère. The term "BDX" comes from the ticketing code for the Bordeaux airport which has flights to Paris, London and other cities. (My strongest memory of BDX is that of a mediocre dinner and a dirty room at a nearby hotel, and a delayed flight resulting in a missed connection from London to Seattle.)
The question here is why there are up to six grape varieties in BDX blends when there are, for all practical purposes, only three in Bordeaux. Here are the percentages of grapes grown in that region: Merlot, 62%; Cabernet Sauvignon, 25%; and Cabernet Franc, 12%. This adds up to 99%, leaving only 1% for all of the Petit Verdot, Malbec and Carménère grown in Bordeaux.
The latter three varietals have Bordeaux origins, but are practically non-existent today. Here's what happened to them.
Petit Verdot - The name means "little green." It is a variety that produces small grapes and ripens slowly, which is why it has fallen out of favor in Bordeaux, a relatively cool climate area. In some years, the grapes do not ripen fully and don't have the beautiful crimson color and perfumed fruit that comes in warmer years. After the phyloxera devestation of the 1870's and '80's, there was little incentive to replant Petit Verdot.
Malbec - At one time, a fair amount of Malbec was grown in Bordeaux, especially in Graves, but the phyloxera devastation led to it's demise. Today, in France, Malbec is grown almost exclusively in the Lot River Valley around the town of Cahors, from which the appellation takes its name. It is also known as "the black wine." Much Malbec is now grown in Argentina which is the world's largest producer of that varietal.
Carménère - This is now known as "the lost grape of Bordeaux." Again, the phyloxera infestation led to its near-extinction. Its resurection has occured in the New World by way of Chile. In the late 19th century, cuttings of what were purported to be Merlot were shipped to Chile, but later, after closer examination, were found to be Carménère. It has more recently developed into something of a cult varietal in the U.S., especially in Washington State.
All this is not to say that there is any problem with calling wines including Petit Verdot, Malbec or Carménère "BDX" blends. But that is more in a historical rather than a contemporary sense. But, at least, those varietals do grow well in Washington State, due to the warmer, more consistent climates than those of Bordeaux, which gives a reason to include them in "BDX" blends.
Here are some noteworthy recently revewed "BDX" blends.
2013 Bartholomew 5th Quarter Blend, Columbia Valley ($32) 19/20 points. (April issue)
55% Carmenénère, 20% Malbec, 10% Cabernet Sauvignon, 8% Petit Verdot, 7% Cabernet Franc.
2014 NumbSkull "BDX" Red Wine, Walla Walla Valley ($38) - 19/20 points. (April issue)
73% Merlot, 20% Cabernet Sauvignon and 20% Merlot
2013 L'Ecole No. 41 "Perigee" Estate Red Wine, Walla Walla Valley ($54) - 19.5/20 points. (April issue)
50% Cabernet Sauvignon, 20% Merlot, 15% Cabefnet Franc, 9% Malbec, 6% Petit Verdot.
2013 Long Shadows "Pirouette" Red Wine, Columbia Valley ($55) 19.5/20 points (December issue)
63% Cabernet Sauvignon, 20% Merlot, 12% Petit Verdot, 9% Cabernet Franc.
Also, there are some fine examples of stand-alone varietals from the Petit Verdot, Malbec and Carménère grapes.
2013 Seven Hills Reserve Petit Verdot, Walla Walla Valley ($45) - 19.5/20 points (to be in the May issue)
2013 Kerloo Cellars Malbec, Wahluke Slope, Stone Tree Vineyard ($40) - 19/20 points (January)
2013 àMaurice Cellars "Amparo" Estate Malbec, Walla Walla Valley ($47) 19.5 points (November)
2014 Seven Hills Carménère, Walla Walla Valley ($30) - 19 points (to be reviewed in May)
2012 Tertulia Cellars Carménère, Horse Heaven Hills, Phinny Hill Vineyard ($40) - 19 points (April)