Fill the fryer with oil and heat to 375 degrees F. Preheat the oven to 200 degrees F.
Cut the cod into 1-by-3-inch strips, using a sharp knife.
Combine the flour, seafood seasoning, baking soda and a pinch salt in a medium bowl. Make a well in the center and gently pour in the beer. Mix until just combined. Working in batches, coat the fish generously in the batter.
Fry the fish in batches until golden brown and crispy, turning the fish over to make sure they fry evenly, about 5 minutes. Transfer immediately to paper towels to blot the excess oil. Season with salt while the fish are still very hot.
Arrange the fish on a baking sheet lined with a cooling rack, and insert a cocktail toothpicks into each piece. Hold in the oven until ready to serve.
Serve with a small dollop of the Salt and Malt Vinegar Aioli on top of the fried cod.
Whisk together the mayonnaise, vinegar, parsley and garlic in a medium bowl until combined. Stir in the salt, adding more to taste, if needed. Reserve until ready to use.