In a large saucepan or deep fryer, heat oil to 375 degrees.
In a large bowl, whisk together flour, milk, beer, eggs, and seasoned salt. The batter will be light and thin.
Working with 6 or 8 cheese curds at a time, add to batter, toss to coat, and remove with a wire strainer. Shake them to remove excess batter.
Drop the curds into the hot oil one at a time and fry until golden brown, about 2 to 3 minutes. Drain on paper towels and serve immediately with ranch dressing if desired.