Recipe adapted from 97 Orchard by Jane Ziegelman (Harper Collins)
Fannie Cohen was an immigrant homemaker from Poland, who arrived in New York in 1912; a married woman with two young kids. It was her habit to prepare more food than her own family could ever consume.
Friday mornings at three a.m. she mixed up a batch of dough for Sabbath challah, using twenty pounds of flour, forty eggs and five cups of oil. By Friday afternoon, Mrs. Cohen had twenty braided loaves cooling by the window. Some she gave to neighbors; the local rabbi always received the two largest, and others she sent to recent Ellis Island arrivees. This is her family recipe, scaled down to yield two good-size loaves.
7 1/2 cups bread flour
Dissolve yeast in warm water; let stand until foamy, about 5 to 10 minutes. Combine with remaining ingredients, stirring to form a dough.
Knead dough for 10 minutes, and then place in a lightly greased bowl. Cover with a damp cloth and let rise until doubled in volume, 1 to 2 hours.
Punch down dough, knead ten times and divide in two.Separate each half into thirds. Roll each section into a rope about 18 inches long. Braid rope, pinching the ends and turning them under.
Place on a lightly greased baking tray and cover with a damp cloth. Let rise until doubled in size.
Preheat oven to 375 F.
Before baking, brush challah with one egg yolk mixed with 1-teaspoon water.
Bake for 45 minutes to 1 hour, until golden brown.