Imperial Porter is a full bodied, very dark, malty beer with a good roasted character coming from the Crystal, Chocolate and Black Patent Malts used in the mash. Warrior, English Fuggles, and East Kent Goldings Hops balance the malts with a good hop bite. The beer has an OG of 1.070, rounding out after fermentation with just a slight residual sweetness and cutting dry at the finish. 7.1% alcohol by volume.
So here’s something to ponder. These days, the "Imperial" designation in American craft brewing connotes an "extreme" factor, typically through higher alcohol content. 7.1% is certainly higher than your typical beer (let’s say 5-6% is typical for a porter), but at the same time, it doesn’t seem strong enough for an "Imperial" designation.
Which begs the question, where is the line drawn at "Imperial"? Is it higher (8-9%+) alcohol? An "extreme beer" characteristic of some sort? Should it be reserved for special edition beers like this that aren’t necessarily monsters but are still special edition?
At any rate, I think this beer is a pretty excellent Porter, not coming at it from any "extreme" angles. I’m sure some aging would do this beer well and the higher alcohol level would come into play more as it ages.
Appearance: Brown-black like dirty motor oil in the glass, deep crimson at the very edges. Fluffy, thick head that’s light brown.
Smell: Roasty malts, cocoa powder, coffee beans. A dusty, nutty character, along with wood and a bourbon note(?).
Taste: Nice dry porter going on here; bitter but not astringent; dark coffee, burnt wood, roasted smoky grains. Mellow hop bitterness—earthy and a tad spicy as befitting English hops. A dusting of bitter cocoa powder accentuates the dry finish.
Mouthfeel: I think it’s pretty spot-on for a porter; light of medium-bodied with a lot of depth; I think the alcohol gives it a bit of an edge. Finishes dry and clean.
Overall: A pretty masterful porter, dark, rich, roasty and dry—like an extra-dark bittersweet chocolate. Top notch, showcasing a lot of brewing experience. (Though I’m judging as a "porter" and not an extreme beer.)
BeerAdvocate, meanwhile, classifies this as a Baltic Porter and so far there are only two reviews. Those two reviews average out to an overall B grade.