There are many great bread and baking sites online. One that I like a lot is Sourdough Home.
Interestingly enough, "sourdough" need not be sour. Indeed, many of the best breads that I know of are not sour at all and are made using sourdough methods, so the term "wild yeast" bread seems quite apt.
People say you should feed your starter twice a day! I absolutely never do this. I store about 1/2 cup of starter in my fridge for weeks on end, then when I get in the mood for sourdough, pull it out and feed it to get it going again as described here. I have had no trouble neglecting it for as much as a month (or more!), but this is not recommended.
If you neglect it a long time, it will get dark on top and a clear fluid (rich in alcohol) known as hooch will accumulate on top. Dump this off, and maybe even scrape some of the dark stuff off the top (I don't always even do this).
What I do to feed mine is to take the starter out of the fridge, maybe let it warm up for a while, then dump it into a good sized glass mixing bowl. Then I add 3/4 cup of plain old tap water and take the time to mix it thoroughly. Then I add 1 cup of all purpose flour, mix that in, cover with clear wrap and let this sit on the counter until it gets going.
This generally will yield enough starter to make either pancakes or biscuits. Once it is active, I remove the 1/2 cup or so I save, and save it. Then I make the recipe with what remains in the bowl. I never discard starter, there is always something you can do with it.
1 cup of starter (or whatever you have) 1 tbsp of sugar 1 egg 1/2 tsp soda 1 tsp baking powder 1/2 tsp salt 1 tbsp oil 3/4 cup milk (or more usually water for me)
1 cup of starter (or whatever you have) 1/2 tsp salt 1/2 tsp soda 2 tsp baking powder 1 cup of flour 4 tbsp butterMix (sift) the dry ingredients, then blend in the butter (I use a food processor). Then mix in the starter and knead in the bowl. Pat to a 3/4 inch thick square, and then cut this 3x3 like a tick-tack-toe pattern. This yields 9 square biscuits. Why hassle with cutting them round, this works great, saves time and who can complain?
Bake at 425 for 12-15 minutes to yield 9 biscuits.
But if you are adventurous, you can brew up your own. I did this once using rye flower and grapefruit juice as described here, but I neglected it and had to start over. The second time I was able to beg some good starter from a local baker.
Here is a great link that talks about how to make a sourdough starter.
It is easy enough (and fascinating) to prepare your own starter. All kinds of methods are offered. It is recommended to start with coarsely ground rye flour, as rye is said to have lots of the organisms that you want to start a sourdough culture. Some people purchase sourdough cultures (King Arthur will sell you a living culture in a plastic jar). Some people just start with flour and water and rely on picking up the yeast and bacteria from the air (or the flour they start with). Some add a bit of yeast, though this is frowned upon by purists.
I am told that certain bacteria can interfere with the successful startup of a proper culture. These are leuconostoc bacteria (and are used in the fermentation of cabbage to produce sauerkraut). In particular, Leuconostoc citreum is a known troublemaker and a gas producer that gives a false impression of success, only to stall 3 days later or so. The recommended trick is to use unsweetened pineapple juice during the first couple of days when making a starter. See this article by Peter Reinhart. Apparently the pineapple juice establishes a pH level that discourages the leuconostoc bacteria, but is favoriable for the yeasts that are desireable in a sourdough starter. There is more about this here. as well as here in a pair of fine articles by Debra Wink. About 1/2 teaspoon of ascorbic acid works well, but many vitamin C pills are buffered and won't yield the pH control that is desired, and finding a source for unbuffered ascorbic acid is problematic. Other bacteria (Aerococcus viridans) do not produce gas, but sometimes proliferate in the early days of starter production. Enterobacter cloacae produce unpleasant smells.
Along with pineapple juice, it is recommended that you stir your starter 2 or 3 times each day for a minute or so. During the "seed" stage this can help avoid bad organisms getting a foothold. The yeasts and desirable lactobacillus are happy with the extra oxygen and the bad bacteria (often on the surface) and especially molds get stirred into the acidic environment and are deactivated.
Another writer suggests that when you get a good starter going, you hedge your bets by freezing some flakes of it in zip-lock bags so that if your starter goes bad or gets invaded by unhappy organisms, you have a "seed" culture to start over with.
There are 4 phases in the development of a sourdough starter from scratch. Note that the initial bacterial stages pave the way for yeasts later.
A typical neglected starter will have a layer of liquid on top, an off colored surface layer, and something resembling the original starter below. The clear liquid on top is "hooch", with a fairly high alcohol content - discard it. The off colored surface layer is best scraped off and discarded. The remaining stuff should be used a spoonful at a time to try to get a new starter going. Save the rest in case this fails and you want to start all over again. There is a lot of acid in a neglected starter and using more than a spoonful is likely to be counterproductive due to the acid you are bringing along.
A neglected starter with mold on top is a difficult case. You want to use many spoons to scrape off the surface layers to avoid mixing mold into the starter.
Go with a spoonfull of old starter, 1/4 cup of water, and 3/8 to 1/2 cup of white flour. Use only white flour when reviving a starter, since it has fewer organisms that might try to compete with the sourdough. Feed this starter 2 or 3 times per day! Your aim is to have the starter doubling between feedings.
Another guideline for revival is the 15/30/50 from Maggie Glezer. You take 15 grams of your old desperate starter, mix with 30 grams of water, and add 50 grams of flour.
80 degrees is a good temperature to get results in 4 days.
Day 1 mix:
2 tablespoons whole grain flour (wheat or rye)
2 tablespoons pineapple juice.
Day 2 add:
2 tablespoons whole grain flour (wheat or rye)
2 tablespoons pineapple juice.
Day 3 add:
2 tablespoons whole grain flour (wheat or rye)
2 tablespoons pineapple juice.
Day 4 (and daily until yeasty) mix:
2 ounces (1/4 cup) of starter (after stirring down, discard the rest).
1 ounce flour (any kind, scant 1/4 cup)
1 ounce water (2 tablespoons)
Tom's Culinary Resources / tom@mmto.org