In a large bowl, combine the active sourdough starter with the milk and softened butter. Slowly add the flour and salt and combine everything to a rough dough.
1 cup active sourdough starter, 4 cups all-purpose flour, 1 cup milk, 1/2 cup butter, 1 tsp salt
Place the dough onto the kitchen bench and knead it for 3 minutes until it's smooth and all ingredients are thoroughly combined.
Add it back to the bowl and let it rest for 15 minutes. Stretch and fold the dough by pulling one edge of it and fold it over. Repeat with all sides.
Place it back in the bowl for another 15 minutes and repeat the process until you have done 3 stretch-and-folds. After that cover the bowl with a damp tea towel or cling wrap and let it rest for 8 hours at room temperature for the dough to ferment. Overnight works well.
The dough will have doubled in size. Remove it from the bowl and divide it into 4 equal parts. Shape each dough portion into a long log with your hands - about 1 inch / 2.5 cm in diameter. Add a little flour if the dough is too sticky to shape it. Cut the roll into 9 pieces with a knife or dough cutter. The pieces should be about 1.5 inches / 4 cm wide.
Preheat the oven to 356F/180C and line 2 large baking trays with parchment paper. Place the dough pieces onto the lined baking trays.
In a large pot, bring the water and baking soda to a boil and reduce it immediately down to a gentle simmer.
1 liter water, 3 tbsp baking soda
Add the dough pieces to the water, about 4 at a time. They will initially sink to the bottom but will slowly float up. Make sure they don't get stuck at the bottom of the pot when they first go into it. After about 10 seconds the pieces will start to float up and you can take them out with a slotted ladle after about 15 seconds. Place them back onto the baking trays. Repeat the process until all pieces had a baking soda water bath.
Add your preferred toppings to the pretzel bites and bake them in the oven for 15 minutes until golden brown. Remove them from the oven and enjoy while warm with your favorite dip!
2 tsp coarse salt, 1 tbsp white sesame, 1/2 cup edam cheese