Autolyse is the process of allowing flour to absorb liquid (generally water). It is not as important when using modern, baker's flour. But if you are baking with whole grains, whole wheat or freshly milled flour it is necessary to allow the flour to absorb the water. This process makes the dough easier to work with. You'll notice that mixing the flour and water and then letting it rest will transform a shaggy, sticky dough into a smooth and pliable dough. While many sourdough bakers choose to the salt and sourdough starter after autolyse, there is no evidence to suggest this actually improves the final product. As such, my recipe sees you add the salt and sourdough starter at autolyse stage - it's quicker, easier and ensures you never forget to add the salt!