We preview the 2009 Four Roses Single Barrel Limited Edition.

'Challenging,' like 'interesting,' is commonly used as a backhanded compliment to describe something of dubious merit which the observer is unprepared to condemn outright. Heavily-peated single malts often receive one or both of those assessments.

But 'challenging' also can mean a creation that requires extra effort from the reader or viewer or, in our case, drinker, an effort which ultimately is rewarded.

Four Roses Bourbon is notable, in its standard expressions, for its exceptional balance, which makes it easy to enjoy. But Four Roses also has had an aggressive limited release program and some of those whiskeys have been challenging, though usually in the good way.

That is the case with the 2009 single barrel limited edition, which won’t be in stores until June.

I got a preview.

The Four Roses Single Barrel Limited Edition 2009 Release will be uncut and not chill filtered. The distillery will be able to produce up to 1,800 bottles, from the super select barrels, that will be distributed in select U.S. markets.

Master Distiller Jim Rutledge specially selected the sophisticated 11-year-old whiskey from among the 10 bourbon recipes the distillery produces.

"We’re excited to continue the tradition of releasing an exceptional, and very unique single barrel limited edition that consists of one recipe we feel exhibits various combinations of flavors and aromas pleasing to any Bourbon enthusiast," said Rutledge.

What makes this release challenging is an unusual bite that persists in the aftertaste. It still has the complex but balanced flavor profile for which Four Roses is famous, but with an edge. I taste citrus, licorice, honey, and wheatgrass, all improbably rolled into one.

This is not a starter bourbon, but most experienced bourbon drinkers should appreciate it.

These releases are very small and typically sell out quickly. The price point will be a little higher than the standard Four Roses Single Barrel, which sells for about $40 a bottle. If you’re interested, it is not too early to alert your favorite whiskey monger and ask them to reserve a bottle for you.

Four Roses is now available in almost 20 U.S. states, and will continue expansion in other markets throughout 2009.