First, you’ll need a starter: a runny mixture of flour, water, yeast and bacteria. It must be regularly “fed” (unlike the mold in your refrigerator, which grows by itself).
Nurturing the starter, and then making the bread itself, is a simple process provided you don’t have anything else in your life, such as a job or children. Allow 48 uninterrupted hours, minimum.
For the actual baking, you can either purchase a $500 Dutch oven pot and $25 parchment paper, or put the dough directly on that old pizza pan crusted with burnt anchovies. Either way, your sourdough bread is bound to disappoint by turning out too flat, dense, fragile and/or pale. Now you know why store-bought loaves cost $5 each.