Fish and Chips With Homemade Tartar Sauce

1/2 on an angle

4 large russet potatoes

1 3/4 cup rice flour

2 teaspoons baking powder

1 teaspoon salt

1 teaspoon sugar

1 bottle (12 oz) beer, pale ale or lager works well

1 cup mayonnaise

1 tablespoon capers, chopped

1 tablespoon cornichons, chopped

2 tablespoons flat leaf parsley, finely chopped

1 tablespoon tarragon, finely chopped

1/2 lemon, juiced Lemon wedges, for serving