Sour Dough Brioche - Basic recipe - 100% success!!

150 g of sour dough
450 g of  flour ( half strong, half plain flour)
200 g of milk
2 eggs
80g sugar (it can be less depending on how sweet you like your brioche to be)
100 g butter at room temperature
1tsp salt

for extra flavour: zest of 1 lemon, vanilla, cinnamon, ginger, all spice, orange zest ... depending on what you will use the recipe for

preparation:

In a planetary mixer dissolve the yeast with the milk, add the egg yolks, flour, sugar, grated lemon peel, and work thoroughly. Once the dough is elastic add  butter (at room temperature)  and salt  and work for about 20 minutes until the dough is well elastic and smooth.
Pot the dough in a bowl and cover it; I usually make the dough in the morning and let it rise until about 8/9 pm; it should be doubled in size, it really depends on room temperature and on the strength of your sour dough.
Once the dough has doubled its size pour it on a floured worktop, flatten it and fold it like in the picture below ( I borrowed the image from on Italian blog)

Left the flatten dough, Right the dough after having being folded

Let it rest for 40 minutes or so and then your dough is ready for whatever recipe you may want to use it for.  I usually shape my brioche bread around 10 pm and bake it and a preheated oven at 200 C the morning after. The time of baking depends on the size of your creation, whether it is a brioche loaf or small croissants or whatever takes your fancy.