A very good Black Strap Rum, unless you want an actual Black Strap Rum...
Cruzan's Diamond Estate Black Strap Rum made a splash in the Tiki world back in 2010 when Giuseppe Gonzalez called it out as his rum of choice in the revamp of the Jungle Bird that became a hit at the now defunct Painkiller in NYC. The bottle and name are new but the black strap rum is the same as it was in 2010.
Which begs the question, "What is black strap rum?" As with most things in Tikidom, it depends upon who you ask. From a distiller/technical point of view it is a rum that is made from Black Strap Molasses. When sugar is made from sugar cane, the cane is crushed making a sweet liquid. That liquid is boiled in a vacuum and then spun in a centrifuge to pull out the sugar crystals (which is brown sugar) however, whats left over is molasses. While not as sweet as brown sugar, molasses is sweet and is still capable of producing more sugar crystals. If we're making sugar and not molasses, the entire process is repeated. After three trips through the centrifuge, the left over molasses is called "Black Strap" molasses. Compared to the initial molasses which has a sugar content around 70%, Black Strap has a sugar content around 45%, is darker in color, and can taste a bit bitter and/or salty. Using this as the basis of your rum is how you make Black Strap Rum.
...except that no one really does that anymore. (Ok, some due... but none of the major distillers do, and even when one does, the resulting rum is clear, not black)
So, "Black Strap" is currently being used as a marketing term to describe rum that is black in color, has a flavor profile that contains molasses and a bit of syrup with notes of raisin, fig, and licorice. It's not as intense as pot still due to the column distillation normally used by those marketing their products as Black Strap (Cruzan, Bacardi, Kraken, etc.). Of course, there are also "black" rums some of which are pot-still made or blends of pot and column still products. Which brings me to the larger point that even this "Black" designation is a marketing term as opposed to a distillation description. We typically think of darker rums as better due to their color being a result of more time spent aging in wooden barrels. However, you could leave rum in there for 50-60 years and it will never get as black in color as most black or black strap rums. In fact most are young rums (less than 3 years old) that have color added to them. Blame Myers, they started it...
Which brings us back to Cruzan's Estate Diamond Black Strap Rum. Where does it fall on this spectrum? Gary Nelthropp, Master Distiller at Cruzan, describes it as a flavored rum with a base of a light 2 year old rum (that does use some black strap molasses in it's fermentation process) that then has flavoring and color added to it. I have often lamented the overuse of flavored rum in Tiki drinks with the notable exception of coconut rum (due to the lack of desire for the creaminess that comes with using actual coconut derivatives in every every drink) and I think this Black Strap falls in a similar category. The flavors added aren't replacing something that can be easily added (like a fruit juice). As a result they make the rum more complex without getting too heavy or so funky as to overpower your other ingredients.
I found Cruzan's Black Strap to have a nose typical of Cruzan's white and gold rums with an overlay of maple syrup. The initial flavor has more molasses but it eases back into the maple syrup on the finish. The heat is typical for an 80 proof product but I can't recommend sipping straight up or on the rocks. But that's not what this rum is made for. It plays exceedingly well in tropical drinks as the sweetness is not the same as fruit-sweet or simple syrup sweet such that they all compliment one another to make a more interesting flavor profile. I found that it worked best with drinks that were on the spiced side of Tiki rather than the light fruit side as it can overpower in something like a Daiquiri. Essentially, anything with bitters, falernum, or orgeat is fair game in my book. And at $18-25 per bottle it's a great addition to anyone's arsenal!