Prepare your little sourdough about 24 hours before making your pancakes. Mix 60 g of main sourdough with 60 gr. of water and 60 gr. of flour. Let it bubble for about 12 hours.Prepare your pancake dough. Pour the flour into a bowl with a pinch of salt. Make a well. Add eggs and beaten butter. Mix by making large movements to aerate the dough and obtain a homogeneous paste.Add your sourdough. Then pour the milk little by little while mixing to avoid making lumps.