Let me start off by saying I'm a big fan of the 21st Amendment (both the brewpub and the amendment, of course); we go way back. They're one of my two favorite brewpubs in San Francisco (the other being Magnolia) - heck, there's even video evidence of my past hanging out there at a F*ckedCompany.com party during the dot-com crash (skip to minute 1.03 if you have a burning desire to see the much-younger me speak). I love that they've been pioneers in canning craft beer, and they are never afraid to experiment. With that in mind, I had high hopes for Back in Black - I love the style, especially Stone Sublimely Self-Righteous Ale, Victory Yakima Twilight and Deschutes Hop in the Dark - and whether you wish to call it a Black IPA, Cascadian Dark Ale or something entirely different is a point I'll leave up to you.
With that somewhat rambling prologue out of the way, I'll get right to the review - I'm disappointed to say it was only OK. It looked great when poured - deep brown, tan head, nice (if somewhat unexpectedly subtle) hop aroma, but when it came to the actual taste, that's where things weren't exactly right. I've sampled some homebrewed beers in this style that don't quite get the hops and roastiness working together as they should, imparting a somewhat ashy taste, and I'm sorry to say I noticed a very similar taste with Back in Black. While that flavor was at the forefront, it also lacked a certain depth beyond that; one of the great things about this style is that there are usually a number of different complementary (granted, some would say competing) tastes, while this was very one-note.
Was it terrible? No - it just wasn't up to the usual very high standard set by the brewery. Sublimely Self-Righteous is still the standard in this category - but it's great to see more brewers jumping on board. A willingness to experiment, even when it's not always 100% successful, is a fine thing - and something that sets the craft beer industry apart.