Q: I've been getting into bread making, and I've been experimenting with sourdough. I've been trying not to use any additional yeast - just the sourdough itself. How can I control the taste of sourdough and how can I control the strength in terms of rising times?
Lynne: Sourdough needs to feed on flour. You can control the acidity because the desirable thing about a sourdough is how the acidity works. There are several types of sourdough. There are many factors involved here, but if you feed it frequently with flour it is going to generally be mellower than if you just keep letting it produce more and more acid. One of the last steps in fermentation is acid. You don't want it to keep fermenting and fermenting until it becomes extremely acidic. It's a misunderstanding that sourdough bread has to be so sour that you pucker. The most traditional method of making bread throughout the world is a flour and water mixture that ferments from wild yeast and becomes the "yeast" for your loaf. So keep adding flour and water to it about once a week.
Q: Does it make a difference what I use to start the sourdough? I'm using a recipe that calls for grapes.
LRK: That recipe tends to have an acid overtone to it. But that's a taste you may like, and that's fine. There's no right or wrong about it! But I suggest you check out a couple books that tell you other methods. Take a look at Dan Leader's By Bread Alone (published by William Morrow) and The Village Baker (by Joe Ortiz and published by Ten Speed Press). Each book will give you different ways to make sourdough bread. There are many ways to make sourdough bread, and they are all fascinating to play with!