In the bowl of a stand mixer, combine all the dough ingredients except the butter. Mix on low speed until the flour is fully hydrated and there’s no dry flour left.
Add the butter one tablespoon at a time, waiting for each piece to mix in before adding the next. Once all the butter is added, increase the speed slightly and continue mixing for about 20 minutes.
Scrape down the sides of the bowl (or move the dough to another bowl), cover with a damp towel or plastic wrap, and let it rest for 30 minutes. Then do 2 to 3 sets of stretch and folds, spaced 30 minutes apart.
Let the dough rise at room temperature until it increases by about 50% in size. This usually takes 6 to 8 hours at around 72°F (22°C).