The recipe yield is:
In large bowl of electric mixer, dissolve yeast in 2-1/2 c water. Add 2-1/2 to 3 c flour; stir 1 minute. Batter will have consistency of soft pudding. Cover bowl tightly with plastic wrap. Let rise in a warm place, free from drafts, overnight or at least 8 hours. The longer the sponge ferments, the better the flavor will be. The next day, stir in salt and 1 to 1-1/2 c of remaining flour. Beat at medium speed with electric mixer 6 minutes, or beat 600 vigorous strokes by hand. Stir in enough remaining flour to make a soft dough. Turn out dough onto a lightly floured surface. Clean and lightly flour bowl. Knead dough 15 to 20 minutes or until smooth, elastic, and no longer sticky. Place dough in floured bowl. Dust surface lightly with flour; cover with a slightly damp towel. Let rise in a warm place, free from drafts, until tripled in bulk, about 1-1/2 hours. Grease 2 large baking sheets or 4 French-bread pans. Punch down dough. Knead 2 minutes. Cover and let rest 10 minutes. For oblong loaves, divide dough into 3 or 4 pieces, depending on desired thickness of loaves. On a lightly floured surface, shape each piece into a smooth log, gently tapering ends. For round loaves, divide dough in half. Shape each half into a smooth ball. Place shaped dough on prepared baking sheets. Cover with a dry towel. Let rise until doubled in bulk, about 1 hour. Adjust oven racks to 2 lowest positions. Place a shallow roasting pan on lowest shelf; pour in 2 c boiling water. Preheat oven 15 minutes to 425-degrees. Slash tops of oblong loaves with 5 diagonal slashes each. Slash tops of each round loaf with 3 horizontal slashes and 3 vertical slashes in a tic-tac-toe design. Brush loaves with cold water. Bake 15 minutes. Brush loaves with egg-white glaze; bake 10 minutes longer. Brush again with egg-white glaze. Remove roasting pan from oven. Bake loaves 10 to 15 minutes longer, for a total of 35 to 40 minutes, or until bread sounds hollow when tapped on bottom. Remove from pans; place loaves directly on oven rack. Bake 5 minutes longer. Cool on racks. Makes 2 to 4 loaves.