In a bowl, add 1 cup flour, 1 tsp paprika, 1 tsp baking powder, 1/2 tsp salt, 1/4 tsp white pepper and whisk to combine. Place to one side.
Cut the tip (not the root) off of your onion with a sharp knife. Peel off the brown skin, then carefully make 1/2" slices along the onion. Pop out the rings, discarding any extremely small ones or any that broke.
One by one, completely coat your onion rings in the flour mixture. Place on one of your wire racks with paper towels underneath (to catch excess flour). Once all rings have been coated in the flour, pour in your 1 cups of beer. Gently whisk to combine.
Don't beat the hell out of it, or you will burst all of the bubbles. Whisk until just combined. A few lumps in the mixture are fine. If you went a little OTT with the beer just add a dash more flour to thicken, and vice versa with the beer. It should be somewhat thin, but thick enough to coat the back of a spoon.
One by one dip the rings into the batter and place on the second wire rack with paper towels underneath. Try and work quickly, you want the batter as bubbly/cold as possible.
Heat up a couple inches of oil in a suitably sized pot/pan until around 375F/190C. Carefully place in 3-4 onions rings (don't overcrowd the pan) and separate if they instantly stick. Allow to fry for 2-3mins, flipping once. Remove and place on your first wire rack with paper towels underneath. Sprinkle with salt to drawer out moisture (optional).