Wash potatoes, peel, cut 1 ¼-inch thick and place in a strainer. Run under running water until the water runs clear.
In a large pot add 8-10 cups of cold water, season with salt and add the potatoes. On medium heat, gently heat up the water, do not let it get to a vigorous boil as it will cause the potatoes to split. Cook for about 20 minutes or when a fork will pass through easily. Using a slotted spoon, carefully remove the cooked potatoes and place them on a cooling rack to dry out. If you have time place in the freezer. If you don not have time make sure to wait until the potatoes have cooled completely.
In a deep fryer, Dutch oven, or large pot heat the oil to 250°F or 120°C.
Add potatoes to the oil and fry in small batches until a light crust forms and they should still look pale. Remove from oil and drain on wire rack with foil or paper towels beneath it.
Put the potatoes back on a wire rack and place them in the freezer for an hour if time allows. If not make sure the potatoes have cooled to room temperature.
When you are ready to cook the fish, place the frozen potatoes in the oil and fry the chips until dark golden at the same time as the fish.
Making the Fish
Preheat vegetable oil in a deep fryer to 350°F or 177°C.
In a large bowl, Mix ⅔ cup flour, rice flour, baking powder, cornstarch, and salt.
Gently whisk the Guinness into the flour, until it doesn't have lumps and is the consistency of pancake batter. Add vodka and gently mix for no longer than 20 seconds.
Season the fish with salt. Add all-purpose flour to a plastic bag, add the fish and gently toss to coat. Shake off the excess the flour. Coat fish in batter, gently place into the deep fryer and cook for 8 to 10 minutes or until golden brown.
Using a slotted spoon gently remove fish from oil on to wire rack or lined plate with a paper towel.