A view of Black Ankle Vineyards in Mount Airy, Maryland. The owners there have had success with their blended wines. (2011 file photo by Michael S. Williamson/The Washington Post)

When Ed Boyce and Sarah O’Herron were blending their 2007 wines, the second vintage for their Black Ankle Vineyards in Mount Airy, Md., six barrels refused to play well with the others. The wines tasted awkward and didn’t add value to the various blends the couple were crafting. So they put the barrels back in storage and forgot about them.

After a few years in barrel detention, however, the wines had “come around,” as wine lovers like to say of late-blooming vino, like troubled teenagers who mature into successful adults. So Boyce and O’Herron blended them with some wine from 2008 and a bit from the super-ripe 2010 vintage. The result was Slate, an unusual melange of Bordeaux grapes — cabernet sauvignon, merlot, cabernet franc, malbec and petit verdot — with syrah comprising a third of the blend. Labeled without a vintage date, the wine was so successful that it won the Maryland Governor’s Cup competition in 2011. It was Black Ankle’s third cup win: Its flagship Bordeaux blend, called Crumbling Rock, won in 2008 and 2009 for the 2006 and 2007 vintages, respectively. The 2010 Crumbling Rock took top honors in the 2013 competition.

Today, Black Ankle offers Slate 2, a blend primarily of wine from the rainy harvest of 2011 (a year when Boyce and O’Herron decided to “declassify” wines and not to make a Crumbling Rock blend) with some from the successful 2010 season blended in.

“If one vintage gives too much alcohol, and the following not enough concentration — as happened in 2010 and 2011 — why not blend them to correct both problems?” Boyce says. “Blending vintages helps our wines avoid being Jekyll and Hyde from year to year.”

The idea of “non-vintage” or “multi-vintage” wines is not new. Champagne producers typically blend wine from three or more harvests to create a house style that can be consistent from year to year in Champagne’s fickle northern climate. If you buy a bottle of Bollinger Brut or Veuve Clicquot Yellow Label, you know what you’re getting. Marietta Cellars in California is up to Lot 62 on its popular Old Vine Red, an old-style zinfandel-based blend. Spanish winemakers traditionally blended the best vintages to make a reserva especial, a technique still used by cult producer Vega-Sicilia.

On Maryland’s Eastern Shore, Bordeleau Vineyards & Winery blends its reds across vintages to achieve consistent quality and has started labeling its wines with lot numbers to distinguish different blends. (However, the winery won this year’s Governor’s Cup competition with a vintage 2008 cabernet sauvignon made with raisined grapes in the style of amarone.)

“Blending multiple vintages gives a winemaker another set of tools to achieve the goal of making excellent wines year in and year out,” says Tom Shelton, Bordeleau’s owner-winemaker.

Federal regulations allow some intermarriage of vintages. When a wine is labeled with an appellation, or American Viticultural Area, 95 percent of it must be from the vintage on the label. However, if it is labeled just with the state of origin, the minimum is 85 percent from the vintage. A skosh here or a dollop there from an older year can add complexity or even a hint of age to a younger wine. Black Ankle’s Slate and Marietta’s Old Vine Red go beyond that minimum and challenge our preconception that fine wine must carry a vintage date.

Vintages might be irrelevant with supermarket wines that emphasize consistency over thrills. Many cheap box wines have abandoned vintages for freshness dates. With fewer people collecting wines to age, do we even pay attention to vintage differences? We might just decide that we don’t like a particular winery any more because this year’s wine wasn’t as enjoyable as the last.

Even so, vintage dating is so ingrained in wine culture that we are unlikely to see a widespread move to vintage blending. Wine fiends love comparing one year with the next, choosing vintages to drink now or to hold. And for winemakers, the year’s weather is part of terroir, that special character of place they try to coax from their vineyards.

In a recent online chat hosted by Frank Morgan, author of the Drink What You Like blog, winemakers from the Veritas, King Family and Grace Estate wineries in Virginia voiced their preference for vintage-dated wines.

“I’m trying to express the character of each vintage,” said Emily Pelton of Veritas — a sentiment echoed by Jake Busching of Grace Estate. Matthieu Finot of King Family expressed it best.

“The wines from 2011” — a rainy harvest — “reflect the vintage,” Finot said. “I don’t want a standardization of my wine to taste the same year after year. “Wine . . . is interesting because of the expression of the vintage.”

McIntyre blogs at dmwineline.com. On Twitter: @dmwine.