I know this is an old thread, but I've made beer cheese soup ALOT and wanted to put in my two cents.
I started with this basic recipe from Emerilhttp://www.foodnetwork.com/recipes/emeril-lagasse/cheddar-and-beer-soup-with-tempura-broccoli-florets-recipe2/index.html
I don't do the broccoli
Over the years, I've made the several adjustments to the recipe:
-Use better beer - personally I like a full bodied stout (nothing too bitter)
-Use beef stock instead of chicken stock for a richer soup
-caramelize the onions
-Use a variety of cheeses, though some won't melt well
-Use a little more beer and less stock if you like
-Use half and half instead of milk if you want it thicker and creamier
As for technique, it's easy to separate the cheese in this recipe and it will take on a "gritty" consistency. I've never fully understood exactly why, but I guess it has to do with getting it too hot once the cheese is in there. If it happens, I just use my immersion blender and it takes care of the problem in just a few seconds.