- In a large bowl, combine the water, sourdough starter and 4 cups of flour.
- Mix well and cover with plastic wrap in a warm place 8-12 hours (I do it over night).
- The next day stir in the salt and sugar and add flour 1/2 to 1 cup at a time to make a very stiff dough .
- Knead till smooth.
- Cover and let rise 2 to 2-1/2 hours.
- Punch down and divide in half.
- Knead till smooth and form into rounds. Place on a greased, or cornmeal dusted baking sheet. Cover lightly and let rise till double and puffy (1 to 1-2 hrs).
- While this is rising mix the 1/2 cup water and 1/2 tsp cornstarch in a small pot and heat until boiling, remove from heat and let cool.
- Heat oven to 400°F.
- Carefully place a small pan of hot water on the bottom rack of the oven.
- Cut two slashes across each other on top of each loaf.
- Bake for 10 minutes.
- Pull out the rack and baste each loaf well with the cornstarch mixture.
- Close the oven and allow to bake another 20-25 minutes. Loaves should be a light golden color and sound hollow when tapped on the bottom.