Sourdough

Starter

• Select a container. A wide-mouthed glass jar is best. Metallic containers are a bad idea; some of them are reactive and can ruin your starter (for the same reason, avoid using metal utensils to stir your starter).
• Blend a cup of warm water and a cup of flour, and pour it into the jar.
• Every 24 Hours, Feed the Starter. You should keep the starter in a warm place; 70-80 degrees Fahrenheit is perfect. This allows the yeast already present in the flour (and in the air) to grow rapidly. Temperatures hotter than 100 degrees or so will kill it. You can take comfort from the fact that almost nothing else will do so. The way you feed the starter is to (A) throw away half of it and then (B) add a half-cup of flour and a half-cup of water. Do this every 24 hours. Within three or four days (it can take longer, a week or more, and it can happen more quickly) you should start getting lots of bubbles throughout, and a pleasant sour or beery smell.
• Refrigerate the Starter. Keep the starter in your fridge, with a lid on it. Allow a little breathing space in the lid. If you're using a mayo or pickle jar, punch a hole in the lid with a nail, that kind of thing. Once the starter is chilled, it needs to be fed only once a week.

Proofing

• Take your starter out of the fridge.
• Pour it into a large glass or plastic bowl.
• Add a cup of warm water and a cup of flour to the bowl.
• Stir well, and set it in a warm place for several hours.
• Watch for Froth and and Sniff. When your sponge is bubbly and has a white froth, and it smells a little sour, it is ready. The longer you let the sponge sit, the more sour flavor you will get.

The proofing-time varies. Some starters can proof up to frothiness in an hour or two. Some take 6-8 hours,

Basic Recipe

• 2 Cups of sponge (proofed starter)
• 3 Cups of unbleached flour
• 2 tablespoons of olive oil or softened margarine
• 4 teaspoons of sugar
• 2 teaspoons of salt

To the sponge, add the sugar, salt, and oil (the oil is optional - you can use softened butter instead, or no oil at all). Mix well, then knead in the flour a half-cup at a time. Knead in enough flour to make a good, flexible bread dough.
Keep in mind that flour amounts are approximate; flour varies in absorbency, and your sponge can vary in wetness. Let the dough rise in a warm place, in a bowl covered loosely with a towel (if you're using a bread machine's dough cycle, let it rise in the machine). Note that sourdough rises more slowly than yeast bread; my starter takes about an hour or so, but some starters take much longer. Let the dough double in bulk. Punch the dough down and knead it a little more. Make a loaf and place it on a baking sheet (lightly greased or sprinkled with cornmeal). Slit the top if you like, and cover the loaf with a paper towel and place it in a warm place to rise again, until doubled in bulk.
Place the pan with the loaf in your oven, and then turn your oven to 350^o Fahrenheit and bake the bread for 30-45 minutes. Do not preheat the oven. The loaf is done when the crust is brown and the bottom sounds hollow when thumped with a wooden spoon. Turn the loaf out onto a cooling rack or a towel and let it cool for an hour before slicing.

Reference

Sourdough Baking- How to Begin - by S. John Ross