The Blackbeard is the creation of Daniel Eun, a bartender at PDT back in 2008. Aquavit and pineapple juice have always had a strange, beautiful friendship; blackberries added to the mix makes for an oddly wonderful triad.
The drink is poured unstrained into the glass, blackberry guts and all. It’s then topped with crushed ice, which forms a sort of lid over the berry matter, keeping it out of your mouth as you sip. Typical cube-ice won’t have this effect; if that’s what you have, you might prefer to double-strain the drink instead of drinking chunks of berry with each mouthful.