Melt butter in a heavy bottom sauce pan. Slowly add the flour while stirring to make a roux. Cook over low heat for a few moments while stirring to prevent sticking. Add the mustard and Schlafly Pale Ale. Continue to stir as the mixture thickens and comes to a low simmer. Let simmer 5 minutes. Slowly whisk in the cheeses and continue stirring until mixture is smooth. Finish with cayenne pepper and Worcestershire sauce. Serve warm or at room temperature with Companion Bavarian Pretzels.