In a large saucepan over medium-high heat, stir together water, sugar and salt. Bring to a boil, whisking constantly and boil for 45 seconds.
Remove from heat and stir in chopped chocolate.
Add vanilla and beer and stir to combine.
Transfer to a blender and blend for 15 seconds.
Refrigerate for at least 4 hours and up to overnight.
Give mixture one final quick blend to incorporate, then transfer to an ice cream maker and churn according to manufacturer's direction.
Transfer to an air tight container, press plastic wrap flush to the surface and chill for several more hours, or until firm but not hard.