To make the sponge, mix the warm milk in a bowl, with the teaspoon of sugar, the yeast envelope and the strength flour. Stir to form a ball of dough. Leave it in a warm place covered with film for 15 minutes or until doubled in volume. To know if it is, put it in a container with warm water and check if it floats. If so, it is ready and ready to go. Put the raisins with the Port in a glass to marinate for a while.
To make the rest of the dough in a bowl, add the sifted flour. Mix the warm milk with the yeast to undo it a little, add it to the flour. Add to the bowl the eggs, the flavored sugar, the salt, the port wine, the butter at room temperature in pieces and finally the well-drained sponge or sourdough. Knead a few minutes with oiled hands and trying not to overload the dough with flour, as it is a slightly sticky dough. Add the drained raisins and dried fruits.
Put the dough for a bowl slightly greased with a little oil and leave it in a warm place covered with a cloth for about six hours. When the dough has doubled in volume, divide it into two portions to knead two small bolo rei or leave it that way for a larger one. Shape it into a thread, the dough must be elastic and not shrink.
Place them on the baking sheets covered with parchment paper (sulphurised). Put in the center a plate greased with margarine or something that resists heat such as a flan or ramekin, so that the hole does not close. Let it rise like this with the form for Two hours more. Preheat the oven to 180ºC.
When they have doubled the volume, brush with the beaten egg carefully, place the chosen nuts, the candied fruits and sprinkle with slightly moistened sugar. Bake for 25 minutesapproximately and cool on a wire rack.