In a large pot over high heat add the sugar, butter and 1/2 cup amber ale, it will triple in volume during the cooking process so make sure to use a large pot. Stir until the mixture starts to boil. Allow to boil untouched until the mixture starts to darken and thicken at about 230 degrees. Stir continuously until it turns a very dark amber and hits 290 degrees. This process will take between 15 and 20 minutes from start to finish. pour onto a baking sheet covered with parchment paper or a Silpat. Allow to cool.

Add the chocolate to a large bowl. Heat the beer until hot but not boiling. You can heat it on a pot on the stove or microwave it in a microwave safe bowl. If you use the microwave, know that the beer will foam up once it reaches it's boiling point. Pour the hot beer over the chocolate chips and stir until well combined and melted.

Pour the chocolate over the toffee and smooth out in an even layer. Sprinkle the crushed pretzels over the chocolate and chill until the chocolate has set. Cut into pieces.