Make poolish the night before (30% of flour, 100% hydration, pinch yeast).
Mix poolish with remaining ingredients briefly then fold until gluten develops.
Set of folds at 15 mins, 30 mins, 1 hour, 1.5 hours.
Bulk until doubled.
Pre shape into tight cigars.
Rest 15 mins, covered.
Shape into baguettes.
Preheat oven to 500 standard.
Rise on couche, covered until risen 50%.
Preheat cast iron in oven on bottom rack.
Boil 2 cups water.
Put risen loaves onto perforated loaf pan on top rack.
Slash loaves.
Put loaves in oven, cover with aluminum roasting pan to trap steam.
Add boiled water to cast iron and close oven quickly.
Steam bake for 12 mins.
Uncover, turn to 500 convection and continue to bake until dark golden.
