Preheat oven to 375.
In a pot over medium heat melt the butter.
Sprinkle with flour, whisk until thickened and light brown in color, about 2 minutes.
Stir in the milk and beer until well combined.
About ¼ cup a time, stir in the cheese, stirring until completely incorporated between additions. Stir in the corn kernels and cornmeal, remove from heat.
In a small bowl whish together the egg yolks (reserve the whites), sour cream, salt, pepper, garlic powder and cayenne. Stir the egg yolk mixture into the corn mixture.
In a separate bowl beat the egg whites until stiff peaks form.
Stir the egg whites into the corn mixture.
Pour the mixture into a greased 2qt baking dish.
Bake at 375 for 30-35 minutes or until the edges start to turn light golden brown.