The night before: poolish

Build this 10 to 14 hours ahead.  There are two ways to seed it: instant yeast or sourdough starter.  

Add the ingredients to a small bowl and mix to a thick batter.  Cover the bowl tightly, and leave at room temperature.  You will know it’s ready when it is noticeably bubbly, domed, and just beginning to sink in the center.  Use all of it.

The dough:

Rest the flour and water. Combine the all-purpose flour, rye, whole wheat, or spelt, and water. Mix until no dry flour remains. Cover and let it rest for 1 hour. This soak softens the whole grain and helps the gluten begin to develop.

Mix in the poolish, salt, and yeast. Add all of the poolish, the salt, and the instant yeast.  Mix into a shaggy dough.  The dough doesn’t need to be smooth at this point.  With the extra water and any whole grain, this will be a slack dough, so the strength will be built with folds rather than kneading it into a ball.

Develop with folds, then rise. Give the dough 2 stretch and folds, about 30 minutes apart. Each time, reach under one side, stretch it up, and fold it over the top, working around the bowl four times or so. After the second fold, cover, and let it rest 30 minutes to 1 hour, until puffy and risen by about half.  Between the soak, the folds, and the rest, the first rise will run about 1.5 to 2 hours.

Divide and rest. Dust your work surface with all-purpose flour. Divide the dough into 2 equal pieces, or more if you want smaller loaves (see Choosing the size of your Tabatière). Shape each piece into a ball without working it too hard.  Cover and rest for 30 minutes.

Pre-shape. Turn each ball so the seam is on top. Bring the edges to the center and press down gently. Turn the dough over and roll it on the work surface, pressing lightly, to form a smooth, even ball. 

Shape the flap. With a rolling pin, flatten and roll about a third of each ball out and away from you, creating a flap (see Choosing the size of your Tabatière for length). Dust the flap lightly with rye, then fold it back over the top of the loaf.

Proof. Place the loaves on a well-floured cloth or a heavily floured work surface, with the flaps underneath. Cover with a damp cloth and proof until puffy and slightly springy, roughly 1 to 1.5 hours.  The dough should hold a slow dent when pressed gently, springing back partway rather than all the way.

Bake with steam. Preheat the oven to 450°F (230°C) with a baking stone on a middle rack and a metal pan on the shelf below or on the oven floor.  A stone provides the best crust and lift, but steam is the part that matters the most, so don’t skip it even if you bake on a baking sheet only. 

Turn the loaves onto parchment, flaps now on top, and score a leaf pattern.  Slide the loaves onto the stone and pour about 50 g (scant 1/4 cup) of hot water into the preheated pan to steam. 

Bake 10 minutes. Then move the loaves up to the rack above, onto a baking sheet, rotating them for even color, and bake until golden and hollow-sounding, about 10 minutes more for small loaves.  Larger loaves will need to bake longer up top (see Choosing the size of your Tabatière).

Cool. Remove the loaf from the oven and place on a wire rack to cool.