In a medium saucepan, melt the butter over medium-low heat.

 Add the onion, bell pepper, and jalapeños and cook, stirring occasionally, until softened, about 5 minutes. Add the garlic and cook for 30 seconds longer. Add the lager, water, cream cheese, and American cheese. Turn down the heat to low and cook, stirring, until the cheese has melted. Reserve¼ cup of crabmeat for garnish and stir in the remaining crab with the cilantro, lime juice, salt, and cayenne. Cook until the crabmeat is warm, a couple of minutes. 

 Taste and adjust the seasonings, if you like. 

 Transfer the queso to a serving bowl, a small slow cooker, or a chafing dish over a flame. Sprinkle with the lime zest, spoon guacamole onto the center of the queso, and top with the reserved crab. Serve warm with tortilla chips.