Buckwheat-Apple-Walnut Bread

Prepare the mise en place for the buckwheat poolish.

To make the buckwheat poolish, combine the bread and buckwheat flours and water with the salt and yeast in a large mixing bowl, stirring with a wooden spoon to blend. When blended, scrape down the edge of the bowl, cover with plastic film, and set aside to ferment at 70°F (20°C) for 14 to 16 hours.

When ready to make th