1. For the preparation of the starter, dissolve the yeast and fine salt in 10 cl of warm water or milk.
2. Add 2 tablespoons of flour. Mix, cover with a cloth, and let it double in size in a warm place.
3. In a bowl, mix the remaining flour with the remaining water or milk and the softened butter.
4. Knead this dough well, then incorporate the starter.
5. Let it rest for 2 hours, covering it with a damp cloth.
6. Take pieces of dough the size of an egg.
7. Roll them into small finger-sized logs, about 40 cm long. Shape them by crossing the ends inward.
8. Let them rest for 20 minutes, then refrigerate the pretzels until the dough slightly firms up.
9. In a large container, boil 1 liter of water and baking soda, then let it cool down.
10. Dip the pretzels in this bath, remove them when they float to the surface, and carefully place them on a buttered baking sheet.
11. Sprinkle them with coarse salt. Bake in a very hot oven (300°C/thermostat 10) for only 8 to 10 minutes.