Is Guinness defying the laws of physics? Not exactly. Every Guinness is supposed to be poured into a specially crafted tulip glass. But that glass is designed to manipulate the bubbles in the beer ...

In fact, it takes :19 before the head-fake is revealed with the super "100% H2O ... proudly pour them one in a nice clean (branded) Guinness glass and hand it to the patron with a wink.

It matters where you grab a pint of Guinness. Boston.com wants to know where Greater Boston drinkers go to drink this stout.