Combine whiskey and saffron; heat to boiling; seep 5 minutes to extract color and flavor. Strain brew through a very fine strainer or wet coffee filter; add water to measure 2/3 cup. Add butter. Heat liquid mixture to 130ºF. In mixing bowl, combine yeast, 1 cup flour and other dry ingredients. Add warmed liquids; mix on medium speed with paddle or beaters for 4 minutes. Add eggs; beat 1 minute; gradually add remaining flour and knead with dough hook(s) 5 to 7 minutes, or by hand, until smooth and elastic. Place dough in lightly oiled bowl; turn to grease top. Cover; let rise until indentation made with finger remains, about 1 hour.
RISING, SHAPING, AND BAKING
Turn dough onto lightly floured surface; punch down. Roll dough into a 24-inch-long rope. Fold the rope in half; twist dough a few times. Place on greased baking sheet or in a greased 9- x 5 inch pan; tuck ends under. Cover; let rise until indentation remains after touching side of dough, about 1 hour. Bake in a preheated oven at 375ºF (325ºF if using a convection oven) for about 25-30 minutes. Cool on rack before slicing.
Baker’s option: Omit whiskey. Pour 2/3 cup boiling water over crushed saffron. Seep for 10 minutes.
