1In medium bowl, beat flour, 1 teaspoon salt, 1/4 teaspoon pepper, the butter and egg yolks with whisk. Gradually add beer, stirring until combined. Cover; refrigerate at least 2 hours.
2Sprinkle zucchini sticks with additional salt; place in colander. Let stand 1 hour.
3Wash and dry zucchini sticks. Immediately before using batter, beat egg whites in small bowl with electric mixer on high speed until stiff. Fold into batter.
4In deep 3-quart saucepan, heat vegetable oil to 375°F. Dip each zucchini stick into batter; place in hot oil. (Do not fry too many pieces at a time.) Fry 2 to 3 minutes or until nicely browned. Remove from oil; drain on paper towel. Sprinkle with salt and pepper. Serve immediately.