Dissolve sugar in warm water, sprinkle dry yeast on top, allow to sit until foaming well.  Stir in whole wheat flour and salt.  Stir in 1½ cups of the unbleached flour.  Continue, adding unbleached flour a little at a time, kneading it in thoroughly.  Use enough flour to bring dough to a firm, elastic consistency.

Cover dough and allow it to rise to double the bulk (approx. 1 hour).

Punch dough down and divide it into two equal portions.  On a lightly floured board, gently stretch the dough into a rectangle and roll the ends toward each other to create a long narrow loaf.  Pinch the ends and seam to seal them and place the dough on a baking sheet (or parchment) sprinkled with corn meal.

Perform the same procedure with the remaining portion of dough. Cover loosely with plastic wrap and allow to rise until the loaf is about 50% larger in diameter (about 30 to 40 minutes).  While loaves are rising, place a baking stone on an oven shelf just below mid-height.  Preheat oven to 375º F (191º C).

When loaves have risen sufficiently, slash the loaves diagonally, ½" (2 cm) deep, six or eight times along the length.

Slide the loaves (and parchment) onto the baking stone to bake about 30 to 35 minutes.  When the baking has started, stir the cornstarch into a quarter cup of water in a Pyrex(tm) baking or measuring cup.  Place the cup in the oven, or microwave it, stirring occasionally until the mixture forms a translucent glaze.  About 15 to 20 minutes into the baking, brush a coat of cornstarch glaze onto the loaves.  Brush another coat on about 4 or 5 minutes before removing the loaves from the oven.  When the loaves are done, place them on a wire rack and cover with a towel until cool.