CRUMBLE saffron threads into melted butter. Let stand 30 minutes for flavor to intensify.
HEAT milk just to a simmer, then immediately remove from heat. Stir in melted butter, sugar, and salt. Pour into mixing bowl and cool until just warm to the touch. Stir in yeast and let stand 10 minutes.
BEAT 3 1/2 cups of flour into yeast mixture. Stir in eggs until well blended. Add just enough of the remaining flour to form a soft dough that pulls away from the sides of the bowl. Dough should be very soft, but not too sticky.
TRANSFER dough to a large, greased bowl and turn to coat all sides. Cover with a clean towel and let rise until double, about 1 hour.
PUNCH down dough. Knead lightly two or three times on a floured surface. Pinch off golf ball size pieces and roll into 1/2-inch think ropes. Shape into S-shapes, coiling the ends. Place on a baking sheet. Cover with a towel and let rise until doubled, about 30 minutes.
PREHEAT oven to 375°F.
BRUSH buns with egg white and place one raisin or currant in the center of each coiled end.
BAKE until golden brown, about 15 to 18 minutes. Wrap airtight to store.