Follow the steps in order for the best result.
Begin by steeping the saffron threads in the warm water to infuse the water with color and flavor. Set aside.
In a large mixing bowl, dissolve the yeast in 1/2 cup of warm water. Add a pinch of sugar to help activate the yeast. Let it sit for a few minutes until foamy.
Add the beaten eggs, evaporated milk, the saffron-infused water (including the threads, drained and crushed), salt, and sugar to the yeast mixture. Mix with an electric mixer or whisk until the saffron is evenly distributed.
Gradually incorporate 4 1/2 cups of flour, mixing until the dough is smooth and elastic.
Stir in the melted butter until it is fully incorporated into the dough.
Add the remaining 4 cups of flour, or enough to create a stiff dough that is easy to handle.
Lightly flour a clean work surface with 1/2 cup of flour. Turn the dough out onto the floured surface, cover it with the mixing bowl, and let it rest for 15 minutes.
Knead the dough until it becomes smooth and elastic, adding more flour sparingly if necessary to prevent sticking.
Place the dough in a greased bowl, turning it to coat the top with grease. Cover the bowl tightly with plastic wrap and refrigerate overnight, or for an extended period.
Divide the dough into 3 equal portions for 3 loaves.
For each tree, roll strands of dough approximately 3/4 long.
Cut two 5 beyond last curl and just touches it. Make 8 or 9 pairs. Roll 8 long; braid for trunk.
Spiral tree: divide dough into 22 parts. Roll each piece into a 6 long lengths, reserving trimmings. Curl both ends of each strand. Shape 6