Whisk beer and flour until smooth. Stir in salt. Add cayenne pepper and granulated garlic to season, if desired. Let batter sit for at least 10 minutes before frying. In a 3-quart saucepan heat 2 inches oil to 375 degrees. Working in batches of 3 or 4 pieces, dredge avocado wedges in batter to coat completely, letting excess drip off, and fry, turning, until golden, about 3 minutes. Transfer to brown paper with tongs to drain and season with salt.
Ready in 40 min.