In shallow pan, soak asparagus in buttermilk 12 to 24 hours. Remove from buttermilk, but do not rinse.
In a large bowl, combine well the egg yolks, beer, flour, cornmeal, salt, cayenne pepper and black pepper. In large deep sided pot, heat oil to 350 degrees F. Meanwhile, in a large clean bowl with an electric mixer, beat egg whites to stiff peaks. Gently fold beaten egg whites into batter mixture. Dip spears, 1 at a time into batter, then carefully lay in oil. Do not overcrowd pan. Fry in batches, if necessary. Fry for 2 to 3 minutes, turning the spears with tongs to ensure even cooking. Drain on a paper towel-lined plate. Sprinkle with sea salt, to taste. Serve immediately with Aioli.
In a food processor, combine all ingredients well. Refrigerate for 1 hour before serving.