In a large bowl, mix together the warm water, sugar, and yeast, and allow the yeast to activate for 5-8 minutes until foamy looking.
Add the flour, oil, salt, and turmeric and knead together for 7 minutes by hand or 4 minutes on medium speed in a stand mixer fitted with a dough hook, yielding a firm, smooth dough.
Transfer the dough into a lightly oiled bowl and cover the bowl with a moistened kitchen towel, keeping it in a warm place for the dough to rise for 60-90 minutes until doubled in size.
Punch the dough down and then divide into equal portions (I divide into 6 portions of about 0.4 lb. Each for braiding a 6-strand challah).
Roll and stretch the dough into long thin ropes about 1 inch side (2.5 cm.) by about 16-18 inches long. Allow the dough to rest for 5 minutes for the gluten to relax.
Press the ends together one one side. You may need to sprinkle in a tiny bit of water to get the ends to fuse together securely
Braid the strands into a nice long braid, pulling gently as you braid to elongate the loaf.
Pinch the ends together, tucking the butt end of the braid under, and transfer the braided loaf onto a lightly oiled, parchment-lined baking pan. Cover the loaf loosely with a clean, moistened kitchen towel to rise for 45-60 minutes until doubled in size. Meanwhile, preheat your oven to 350°F (175°C).
Once the oven is preheated, bake the loaf for 30-35 minutes until golden brown.
Meanwhile, stir together the olive oil and agave nectar.
Once the bread is lightly golden brown and cooked through, remove the loaf and brush thoroughly with the agave and olive oil.
Finish baking for 4-5 minutes and then remove the loaf, placing it on a wire rack to cool to room temperature before serving.