Sift the flours and salt into a bowl. Add the yeast to 2 1/2 cup lukewarm water in another bowl and stir. Gradually beat in half the flour mixture to form a batter. Cover with clear film and leave for about 3 hours or until nearly trebled in size.
Add the remaining flour a little at a time, beating with your hand. Turn out on to a lightly floured surface and knead for 8-10 minutes to form a moist dough. Place in a lightly oiled bowl, cover with lightly oiled clear film and leave to rise, in a warm place, for about 1 hour.
Knock back (punch down)the dough, turn out onto a floured surface and divide into 3 equal pieces. Shape each into a ball and then into a 6x3 inch rectangle. Fold the bottom third up lengthways and the top third down and press down. Seal the edges. Repeat tow or three more times until each loaf is oblong. Leave to rest in between folding for a few minutes.
Gently stretch each piece of dough into a 13-14 inch loaf. Pleat a floured dishtowel on a baking sheet to make three molds for the loaves. Place the loaves between the pleats, cover with lightly oiled clear film and leave to rise in a warm place for 45-60 minutes.
Preheat oven to maximum, at least 450. Roll the loaves on to a baking sheet spaced well apart. Slash the top of each loaf diagonally several times. Place at the top of the oven, spray the inside of the oven with water and bake for 20-25 minutes.