From Cooks Illustrated March 2004
The batter must be made 12 to 24 hours in advance. They prefer this recipe in a regular waffle iron but a Belgian waffle iron will also work it just makes fewer waffles (that's what we use). These are best served fresh. These waffles are quite rich so we usually skip the butter. We love the crispiness and airiness the yeast creates.
1¾ cups whole milk , or low-fat milk, or skim milk
8 tablespoons unsalted butter , cut into 8 pieces
2 cups unbleached all-purpose flour (10 ounces)
1 tablespoon granulated sugar
1 teaspoon table salt
1½ teaspoons instant yeast
2 large eggs
1teaspoon vanilla extract
1. Heat milk and butter in small saucepan over medium-low heat until butter is melted, 3 to 5 minutes. Cool milk/butter mixture until warm to touch. Meanwhile, whisk flour, sugar, salt, and yeast in large bowl to combine. Gradually whisk warm milk/butter mixture into flour mixture; continue to whisk until batter is smooth. In small bowl, whisk eggs and vanilla until combined, then add egg mixture to batter and whisk until incorporated. Scrape down sides of bowl with rubber spatula, cover bowl with plastic wrap, and refrigerate at least 12 and up to 24 hours.
2. Preheat the waffle iron; remove waffle batter from refrigerator when waffle iron is hot (batter will be foamy and doubled in size). Whisk batter to recombine (batter will deflate). Bake waffles and serve immediately or hold in low temperature oven . To do this, place them on a wire rack set above a baking sheet, cover them with a clean kitchen towel, and place the baking sheet in a 200-degree oven. When the final waffle is in the iron, remove the towel to allow the waffles to crisp for a few minutes in the oven before serving.