Pan de Mie (Loaf Bread) au Levain

Ingredients:

dried yeast 5 grams or dried levain* 10 grams  + fresh levain (sourdough starter) 120 grams
20 cl (ml) lukewarm water
10 cl(ml) milk
500 grams flour(T55 or T65)
8 grams fine salt
25 grams sugar
40 grams softened butter

50 grams of flour for dusting
10 grams of butter for  greasing the baking mold/pan

* levain Blé Bio(organic yeast) : 2 kg flour  = 85 grams (est. 500 grams flour = 20 grams) temps de levée 3h

Procedures:

1.  Mix the flour, salt, sugar.
2.  Add warm milk, water, dried yeast/levain, fresh levain, melted butter   stand mixer low speed for 3 minutes and 7 minutes medium speed
3.  Cover the mixing bowl  let the dough rise until it is double in size. Note; Levain takes time to rise  3 hours minimum.
4. Degaz/punch the dough and