Step 1

Whisk flour, salt, and yeast together in large bowl. Add water, lager, and vinegar. Using rubber spatula, fold mixture, scraping up dry flour from bottom of bowl until shaggy ball forms. Cover bowl with plastic wrap and let sit at room temperature for at least 8 hours or up to 18 hours.

Step 2

Lay 18 by 12-inch sheet of parchment paper on counter and spray with oil spray. Transfer dough to lightly floured counter and knead 10 to 15 times. Shape dough into ball by pulling edges into middle. Transfer dough, seam side down, to center of parchment and spray surface of dough with oil spray. Pick up dough by lifting parchment overhang and lower into heavy-bottomed Dutch oven (let any excess parchment hang over pot edge). Cover loosely with plastic and let rise at room temperature until dough has doubled in size and does not readily spring back when poked with finger, about 2 hours.

Step 3

Adjust oven rack to middle position. Remove plastic from pot. Lightly flour top of dough and, using razor blade or sharp knife, make one 6-inch-long, 1/2-inch-deep slit along top of dough. Cover pot and place in oven. Heat oven to 425 degrees. Bake bread for 30 minutes (starting timing as soon as you turn on oven).

Step 4

Remove lid and continue to bake until loaf is deep brown and registers 210 degrees, 20 to 30 minutes longer. Carefully remove bread from pot; transfer to wire rack and let cool completely, about 2 hours.