My own private sourdough (and this concludes post-punk punning for this post), baked in my own oven with my own home-grown sourdough starter. I added no baking soda, as many recipes call for, and it turned out fine, with a chewy crumb and a mellow sour flavor. The other half of this batch became a fine pizza crust.
Making sourdough is easy. Mix about a cup of organic rye flour with a cup or so of spring or filtered water and a little salt, stick it in the fridge in a container with room for the starter to grow, and go on a trip for a week. When you come back, the near batter should be bubbly with a slight sour odor. To achieve a stronger sourdough taste, it helps to let the starter you plan to use sit out at room temperature for awhile (overnight or most of a day, depending on your baking schedule). I keep my starter in the fridge and feed it about once a week. (You only need the rye to get it started. You can feed it all purpose after that.)
To make a loaf, I mix several flours (usually King Arthur all purpose, about a cup of whole wheat, a little extra gluten, and a couple tablespoons of flax meal), add water and about half my starter, blend and knead thoroughly until it feels good and springy, and let it rise 8-12 hours before I work it gently into a loaf and proof it for one to two hours. I bake it on parchment and pizza stone in a preheated steam-treated oven (500 degrees F, then drop it to 450) until it looks right, about half an hour, and let it sit a couple of hours to finish the loaf.
Note: I don't measure anything, so don't ask, or check out the reference below. To steam, put cast iron pan in the oven before you preheat; and carefully pour a cup or two of hot water in it after you place the loaf on the stone. I read Local Breads: Sourdough and Whole-Grain Recipes from Europe's Best Artisan Bakers By Daniel Leader, Lauren Chattman (Thanks Elizabeth) before I started, but I've modified most of the instructions to fit my kitchen and taste preferences.