The 2015 expression of Samuel Adams’ most extreme beer is the fifth time we’ve covered it — the first was the 2007 vintage — and it may just be the best Utopias we’ve seen to date.

Not familiar with the idea? Here’s some background:

Only the ninth batch brewed since the first release in 2002, this year’s Utopias, like previous vintages, was brewed in small batches using traditional methods, blended with previous vintages going as far back as 1992, then finished in the Barrel Room at the Samuel Adams Boston Brewery.

With each new batch of Utopias, the brewers at Sam Adams push for a complex flavor profile, and during this process have created brews with alcohol levels reaching over 30% ABV; this year’s beer is 28% ABV and is best enjoyed as a two ounce pour in a snifter glass at room temperature. While some of the barrels have reached over 30% alcohol, the brewers blend down because the goal is to craft complex flavors, not an extreme alcohol percentage.

For the 2015 Utopias, the Sam Adams brewers used a variety of malts for the brewing process and during fermentation used several strains of yeast, including one traditionally reserved for champagne. The beer was then blended with Utopias vintages from previous years including some that have been aging for more than 20 years in the Barrel Room. Aging the beer over a longer period of time accentuates the beer’s distinct vanilla notes and creates aromas of ginger and cinnamon. Some of this aged beer is over twenty years old, old enough to drink itself.

Utopias is brewed using traditional methods. The brewers begin with a blend of two-row Caramel and Munich malts that imparts a rich, deep amber color. Noble hops – Hallertau Mittelfrueh, Spalt Spalter and Tettnang Tettnanger – are also added to lend complexity and balance. During fermentation, several yeast strains are used, including one normally reserved for champagne which the brewers call a “ninja yeast.” This fresh beer is then blended with a variety of different barrel-aged beers and “finished” in a variety of barrels to impart additional complexity and flavor.

This release of Samuel Adams Utopias also uses a blend of beer finished in a variety of barrels. “Finishing” is a creative way for the brewers to impart additional flavor from a variety of barrels before the beer is bottled. This final step of finishing the beer lasts several months before the beer is bottled and imparts flavors ranging from fruit like cherry and raisin to chocolate, leather and oak. The multi-step and lengthy process results in flavors reminiscent of a rich vintage Port, fine Cognac, or aged Sherry, while feeling surprisingly light on the palate.

New this year, the brewers used White Carcavelos wine barrels to finish the beer, in addition to barrels that once housed cognac, Armagnac, ruby port, sweet Madeira, and Buffalo Trace Bourbon. White Carcavelos wine barrels help to amplify the dried fruit and oak flavors of this year’s Utopias. Carcavelos wines are blended and fortified like a port, are off dry and topaz colored with nutty aromas and flavors. Carcavelos comes from a small region of Portugal and the barrels are very rare, which made the Sam Adams brewers all the more excited to experiment with them as finishing barrels.

Whew!

With all that out of the way, let’s tuck into a glass of Utopias 2015. Notes of plum, Port-like raisin, and milk chocolate lead the way into as the beer starts to develop in the glass. This can quickly become overwhelming, so use caution as you sip your way through a small glass of the stuff, and watch for exotic mushroom notes, burnt coffee, and raspberry jam.

The finish is where things go a bit off the track, with Utopias 2015 showing slightly sour notes of cherry pits and rotten fruit, as if things have been pushed a bit too far and only dialed back via a last minute rescue. It doesn’t ruin the experience, but it does put a damper on what is initially a pretty glorious beverage.

Utopias isn’t something I drink every day, but it sure is a fun diversion from IPA and winter brews — and one hell of a conversation piece.

28% abv.

B+ / $199 / samueladams.com