Preparation Bring beer just to a boil in a small heavy saucepan, then remove from heat. Whisk together yolks, brown sugar, and a pinch of salt in a medium bowl until combined well. Whisk in cream and vanilla, then add hot beer in a slow stream, whisking constantly. Transfer to saucepan and cook over moderately low heat, stirring constantly with a wooden spoon, until custard is thickened and registers 175°F on thermometer (do not let boil), about 5 minutes. Pour custard sauce through a fine-mesh sieve into a metal bowl, then set bowl in a larger bowl of ice and cold water and stir until cool. Remove from ice bath and refrigerate, covered, until cold, at least 1 hour. Cooks' note:Sauce can be chilled up to 2 days.
Preparation Bring beer just to a boil in a small heavy saucepan, then remove from heat. Whisk together yolks, brown sugar, and a pinch of salt in a medium bowl until combined well. Whisk in cream and vanilla, then add hot beer in a slow stream, whisking constantly. Transfer to saucepan and cook over moderately low heat, stirring constantly with a wooden spoon, until custard is thickened and registers 175°F on thermometer (do not let boil), about 5 minutes. Pour custard sauce through a fine-mesh sieve into a metal bowl, then set bowl in a larger bowl of ice and cold water and stir until cool. Remove from ice bath and refrigerate, covered, until cold, at least 1 hour. Cooks' note:Sauce can be chilled up to 2 days.