Mix 33g mature sourdough starter, 66g water and 66g bread flour until it's completely mixed in a tall glass container.
Put an elastic band around the container so you can monitor the growth. Let it grow to its peak.
Autolyse
Put 685g bread flour in a bowl. Add 15g salt on top. Mix it with your fingers.
Add 335g water, stick your index and middle finger in the dough and move in circles. Pick up a little more flour for each revolution until the dough comes together.
Dump it on your kitchen counter and knead all the flour into the dough (4-5 minutes).
Form a boule and put the dough back in the bowl. Let it rest covered until the levain has grown.
Cube butter
About ½ hour before the levain is ready, take 75g of butter out of the fridge and cut it into cubes. Leave it to come up to temperature on the kitchen counter.
Mix dough
When the levain has peaked, put the boule on the kitchen counter and scatter the levain on top.
Knead it into the dough. About 5-6 minutes. Leave it to rest covered for about 30 minutes.
Knead butter into the dough
Take the dough out of the bowl and add to your kitchen counter.
Push it into a disk shape and add a couple of butter cubes along the edge.
Seal all the butter in by flipping the edge over the dough.
Then knead the dough until the butter is incorporated.
Then repeat by making a disk and kneading in more butter until all the butter has been incorporated into the dough (6-7 minutes).
Then form the dough into a boule, put it back in the bowl, and let it rest covered for 30 minutes.
Divide and preshape
Divide the dough into 12 equally sized pieces, about 100g each.
Put the dough under a wet cloth to prevent it from forming skin.
Take each piece of dough and form a small ball this way:
Push the dough into the center at the bottom of the ball. Turn the ball about an ⅛ and repeat until you have a reasonably taut surface.
Then put the ball down on your counter and put your hand over the top like a claw, and move it in circles to make a perfect ball.
Put it back under the cloth and shape the other 11 pieces of dough the same way.
Leave them to rest for 30 minutes to relax the gluten.
Final shape
Take one ball and roll it out to a long strand of dough, about 1 meter/3 feet 4 inches. It should be thicker in the middle.
Lift the ends, cross them and put them down on the table, and cross the strands.
Lift the ends, flip them down to the lower part and place the ends decoratively.
I recommend that you watch the video on the shaping. The shaping is the hard part.
Put six pretzels on one baking sheet, cover it with cling film and do the same with the other 6.
Final proof
Leave to proof on the counter for about 2 hours. They should have visibly grown.
Then move into the freezer for 30 minutes. If you don't have room in the freezer, you can use the fridge. This step is to help keep the carefully shaped pretzels intact.
Heat your oven to 230°C/450°F using the fan assist. If you don't have fan assist go to 240°C/475°F.
The dipping and baking
Before the 30 minutes are up, put on safety gear (gloves and glasses), add 1 liter (about 4¼ cups) of water to a non-reactive bowl, and add 30g of foodgrade lye.
Mix it with a wooden spoon until all the lye granules have been dissolved.
Then grab the sheets of pretzels from the freezer.
I put two in at a time for about 30 seconds.
Put them back on the baking sheet on the parchment paper.
Once you've dipped them all, drizzle them with flaky salt.
Score the pretzels in the thick part with a swift and relatively deep cut.
Put the first pan in the oven and bake for 10 minutes. Then turn your oven down to 220°C/425°F. Rotate the pan do you get even browning.
Bake for another 8 to 12 minutes until they are deeply caramelized and done.
While the first tray is baking prepare the other 6 pretzels by dipping them in lye and putting them back on the sheet.
Let all the pretzels cool on a wire rack.
Dispose of your lye solution by pouring it into the toilet and flushing.