The egg whites cause the waffles to puff up and then fall quickly, so serve each piece as it finishes cooking. Jumbo eggs work best, but you can substitute 2 large yolks and 4 large whites.

• 1½ cups whole milk
• 2 tablespoons white vinegar
• 2 jumbo eggs, separated, plus 1 jumbo egg white
• 1 cup all-purpose flour
• ¾ cup sour cream
• 2 tablespoons coarse cornmeal
• 1 teaspoon baking soda
• 5 tablespoons salted butter, melted
• Vegetable oil cooking spray, for waffle iron

1. Preheat a waffle iron on the highest setting.
2. Stir together milk and vinegar; let stand for 5 minutes to thicken.
3. Mix together yolks, flour, sour cream, cornmeal, and baking soda.
4. Stir in milk-vinegar mixture. Stir butter into batter (do not overmix).
5. Beat whites with a mixer on high speed until stiff peaks form. Stir half into batter. Gently fold in remaining whites with a rubber spatula.
6. Coat waffle iron with cooking spray. Pour 1 cup batter into waffle iron (it should be three-quarters full). Close lid, and cook until waffle is golden and crisp, about 6 minutes.
7. Remove waffle from iron. Quickly toss between your hands to release steam and help retain crispness, and serve. Repeat with remaining batter.

Makes 6.