In a small bowl, add the warm water, 1 tbs of sugar and 1 tbs of yeast and stir. Let it sit for about 5 minutes, until frothy.

In a mixer with the dough attachment, add 4 1/2 cups of flour, sugar and salt. In a separate bowl, mix the wet ingredients (butter, yeast mixture and eggs), then slowly add them to the mixer, scraping the sides as you go.

Slowly mix in the remaining 1 to 1½ cups of flour. Continue mixing for about 8 minutes, adding just enough flour so the dough is soft but not sticky.

Form into a ball and place in a large, oiled bowl, turning once to coat. Cover with a clean towel and let it rise in a warm spot for about 2 hours, or until doubled in size.

Punch down the dough and divide it into 4 equal pieces. Roll each piece into a 17-inch rope and place them side by side on a parchment-lined baking sheet.

To braid: pinch the ends together at the top, then take the far-right rope and cross it over the two ropes to its left. Next, take the far-left rope and cross it over the two ropes to its right. Continue alternating sides until fully braided. Pinch the ends together and tuck them under.

Cover the loaf with a clean towel and let it rise for another 45 to 60 minutes, until doubled in size and puffy.

Preheat the oven to 350°F and position a rack in the lower third. Brush the challah generously with the egg wash and bake for 35 to 40 minutes, until golden brown and it sounds hollow when tapped on the bottom.

Let your challah cool completely on a wire rack.