Rich Sourdough Barches. Adapted from Inside the Jewish Bakery: Recipes and Memories From the Golden Age of Jewish Baking
Several days before you plan to bake the challah, start by making sourdough starter. Here’s a recipe for starter from Joy of Cooking:
One package dry active yeast
2 cups warm water
2 cups all-purpose flour
Mix together in a nonmetallic bowl using a wooden spoon. Let stand lightly covered in a warm place for 4-7 days, stirring once a day. When it bubbles and emits a pleasantly sour smell, it’s ready to use. If it turns green or orange or blue, throw it out and start again.
To replenish, discard all but one cup of the starter and wash the crock well. Add the remaining cup of starter from your first batch to 1 cup all-purpose flour and 1 cup lukewarm water. Let stand overnight until fermented and bubbling and then use or refrigerate.
Once your sourdough starter is ready, proceed with the rest of the recipe for Rich Sourdough Barches:
The evening before you plan to bake the challah, make the “sponge”:
1 2/3 cups of bread flour
1 cup warm water
4 Tbsp. sourdough starter, from recipe above
Combine flour water and starter in medium-sized bowl. Cover and leave in warm place until it doubles in bulk and is soft and bubbling on the surface, 8-12 hours. This is called the sponge.
The following morning, mix the sponge with a wooden spoon, and then continue with the rest of the recipe:
5 cups bread or all-purpose flour
3 1/4 tsp. table salt
5 Tbsp. sugar
2 tsp. instant yeast
4 large eggs (3 for dough, 1 for glaze)
1/3 cup oil
2 Tbsp. seeds (sesame, poppy, black nigella, or a combination) for sprinkling
Combine flour, salt, sugar, and instant yeast and blend for 1 minute. Combine sourdough sponge with vegetable oil and 3 of the eggs, beaten, and add to dry ingredients. Using a dough hook, knead at low setting for about 10 minutes until the dough forms a smooth glossy ball that leaves the sides of the bowl, or knead by hand on a well-floured work surface for 12-14 minutes.
Form dough into ball, put into greased bowl and cover with damp towel, and allow to rise until doubled in bulk, about 1 hour. Braid and then let the loaves relax for approximately 40 minutes. Brush with remaining egg, beaten, and sprinkle with seeds.
Bake in preheated oven at 350F until both sides are brown, approximately 35-40 minutes. (For rolls, bake 25-30 minutes.) Transfer to wire rack and let cool before cutting.
Yield two loaves or 12-15 rolls.