Ingredients--Sourdough Starter

Sourdough starter is easy to buy, and relatively easy to make. I've done both.

What you need to know about starter is that it's a combination of wild yeasts and bacteria. The yeasts are probably already on the flour (some bakers think they come from the air, and I don't believe either theory has been proved.)

The bacteria are related to the ones that turn milk into yogurt. Not the same--you can't use yogurt or yogurt starter for sourdough starter. They're in the same family, though. There are lots of ideas about where the bacteria come from.

Not too surprising--the yeast make the bread rise, and the bacteria make it sour.

However, like many roommates, they differ when it comes to what they like. The bacteria like it warmer--around 92F (33C). The yeast like the heat turned down a little--more like 82F (28C). The temperatures for them to reproduce and spread are slightly lower than the best temperature for them to ferment the bread dough.

You can do a lot of fine tuning with this, but in real life, you'll probably get your best results at about 85 degrees F (29C)--at least as far as I know now. I do plan to do some experiments, and will correct this opinion if I come up with something better.

If you buy a starter--which is what a fair number of bakers recommend that beginners do--follow the directions of the company that made the starter. They'll tell you how to get it going well.

Good vendors for sourdough starter are King Arthur Flour and Sourdough International. Both sell on the Internet. The starter I use most often is the SDI San Francisco starter, but I've used the KA one, and it's good, too. You can also buy sourdough starter in many grocery stores, health food stores, and cooking stores.

To make a starter, combine equal parts of whole wheat flour and distilled or spring water. (Whether tap water will work is controversial. Apparently, some tap water works and some doesn't.) I use one cup of each.

Cover, but not tightly. The microorganisms need air. Keep the mixture at 85 degrees until it's bubbly and sour smelling. This will take a couple of days.

Salt rising bread starter is similar, but made with cornmeal instead of wheat. You have to use health food cornmeal--the ordinary kind has been processed in some way that kills the bacteria. I was very confused about this at first, because my recipe (Joy of Cooking) called for "water ground cornmeal," and as far as I could tell, it didn't exist. Finally I tried stone ground, and it worked fine. The brand I generally use is Bob's Red Mill, but probably any organic or health food brand would work. The liquid in salt rising bread starter is whole milk rather than water.

There's a potato starter for salt rising bread, also, but I've never tried it. The cornmeal seems much easier.