In large bowl, beat together yeast or starter and warm milk.

Add 4 eggs, sugar, lemon zest and mix until combined.

In medium bowl, combine flour and salt.

Add flour to egg mixture with stiff spatula and mix dough until flour is nearly absorbed. Add butter and mix to incorporate into dough.

Transfer dough with help of bowl scraper to work surface lightly dusted with flour. Knead dough briefly until smooth, about five times. Place dough back in bowl and seal tightly with plastic wrap.

For yeast bread, let dough rise for 2 hours. For sourdough bread, let dough rise for 10 to 15 hours.

Prepare baking sheet lined with parchment paper.

Lightly dust hands and work surface with flour. Divide dough into three pieces of equal size. Working quickly, fold and roll pieces of dough into tight ropes measuring about 20 inches long, lifting dough as you go. Try to maintain even thickness in each rope. Transfer ropes to baking sheet and join ends farthest from you. Cross left strand over middle, then place right strand over new middle strand, and continue braiding until end. Press ends closest to you and tuck them under to finish braid.

For round loaf, divide dough into two pieces and roll out to 30-in. long ropes. Arrange centers of strips on top of each other to form x-shape. Cross them over to braid up to each end of dough. Coil braid tightly into round shape, pressing end in to seal.

Cover bread tightly with buttered plastic wrap. For yeast bread, let dough rise for 1 hour. For sourdough bread, let dough rise for 2 hours.

Preheat oven to 350 degrees F.

In small bowl, beat 1 egg white together with tablespoon of milk. Brush bread and decorate with sugar, sprinkles or slivered almonds. Generously coat with egg wash.

Bake for 30 to 40 minutes until deeply golden.

Let bread cool completely before slicing.