1. In a large mixing bowl, dissolve sugar in warm water, then stir in yeast. Allow to proof until yeast resembles a creamy foam.
2. Mix oil into the yeast, then beat in eggs, one at a time, with salt. Gradually add flour to form a soft dough.
3. Knead dough on a floured surface until smooth. Place in a well-oiled bowl, cover with a damp cloth, and let rise until doubled in size, about 1 hour.
4. Punch down the dough, divide into 6 pieces, and roll into long ropes. Braid the ropes to form the challah.
5. Place braided loaf on a greased baking sheet, cover, and let rise for another hour.
6. Preheat oven to 375°F (190°C). Brush loaf with beaten egg for a shiny finish.
7. Bake in preheated oven for 30 to 40 minutes, or until golden brown.