I was given a copy of Carol Field's 'The Italian Baker' for Christmas, and have been working my way through her recipes for Italian regional breads, as well as converting some of them to sourdough. (She seems to have a bias against naturally leavened breads and refers to the technique repeatedly as terribly complicated).
The recipe she gives for Pane Francese uses a commercial yeast Biga, and she mentions that she adapted it from a sourdough recipe. I have attempted to convert it back to sourdough.
It is essentially a high hydration (69%) sourdough white bread (with a little wholemeal flour for flavour). The dough is very soft and sticky, and the technique I used for dealing with it is based on Dan Lepard's (The Handmade Loaf).
Starter - you need 180g of starter at 80% hydration. This is what I did to obtain this:
30g bread flour
(stir to paste, leave at room temperature for 12 hours)
Then add 50g water, 100g flour
Mix to a paste, leave for ten minutes.
Pour a teaspoon of olive oil onto a clean board or surface.
Knead the soft dough for ~10 seconds. Return to bowl, cover and leave for 12-24 hours. (This will yield a little more starter than is actually required for the recipe)
180g starter (36%)
350g water (70%)
65g wholemeal flour (13%)
435g white bread flour (87%)
10g (2tsp) salt (2%)
Mix the starter and water, add the flours and salt and combine to a ragged mess. Cover and leave for 10 minutes.
Turn out onto an oiled surface and knead for 10 seconds. Leave for 10 minutes
Knead for 10 seconds, leave for 10 minutes
Knead for 10 seconds, leave for 30 minutes.
Fold the dough. (Following Mick - bethesdabaker's example I usually do a double fold. Lift the dough up by one end and let it stretch under its own weight. Pick up the other end and do the same. Fold one end in by a third. Fold the other end over the top. Turn the dough 90 degrees and repeat the stretching and folding). Cover and leave for 1 hour.
Fold. Leave for one hour
Fold. Leave for one hour.
Shape the dough.
Divide in two. place on a floured surface and roll up into a tight cylinder. Dimple the surface vigorously with fingertips, and place the dough seam-side up on a piece of greaseproof paper, or a linen towel (generously coated with rye flour). Cover
[At this point I usually put the dough in the fridge overnight]
Leave to rise for ~4 hours at room temperature.
Preheat oven to 210C
Gently invert the dough onto a peel (sprinkled with semolina). Transfer onto heated stone.
Add a cup full of boiling water onto a hot tray at the bottom of the oven.
Bake for ~30 minutes
I usually make my starter at 100% hydration, but the Biga used in Italian breads is more like a soft dough. I have replicated that in the recipe above, but I don't know if it makes any difference.
Carol Field uses unbleached all-purpose flour, but to date I have only used white bread flour (Manildra).
Edit: photo added