Now it’s time to add the salt. Salt does two things. It adds flavor, and it helps tighten the gluten and starts giving strength to your dough. If you mix by hand, you can start feeling the differences in your dough as it gains strength. This is important and part of the Baker’s Mind that you want to develop.
I mix my salt in the same way that I do with my levain. I first sprinkle the salt all over the top of my dough. Then I wet my hands, and take my fingertips and dimple the salt into the dough with my fingertips. The goal of this step is to incorporate the salt throughout your dough. To do this, I use my hand a pull up and stretch over a section of the dough. I then turn the bowl a bit and do this again turning the bowl a bit each time.
Once I’ve gone all the way around the bowl, I use the tips of my fingers to pull up a piece of dough, and squeeze it a bit between my thumb and fingers while pulling gently at the dough. I do this over and over while turning the bowl a bit or moving my hand a bit to get to a new piece of dough. Every few times I do this, I take all four fingers and go under the dough to the middle and pull and stretch the dough gently. This is called the Rubaud method that was invented or popularized by @trevorjaywilson. I do these two things over and over until the dough starts feeling and looking smooth and homogenous.
I cover my bowl at this point and let it rest for 30 minutes. It’s good to measure the temperature of your dough at this point and make a note of it.