My daughter thinks this is the grossest thing in my kitchen!
Sourdough starter is your own private, living little yeast colony. You can search the web and find all kinds of sourdough info, but it all begins with a good starter and something to keep it in.
I'm currently using (and loving) this old coffee pot saved from an old coffee maker that died. I can see how much starter I have and exactly what it's doing. I've used a variety of containers over the years. I've had this starter going for about a year and a half. When it gets tired, out it goes and I start a new one.
So how do you start it?
2 cups flour
2 cups water
1 package yeast
Stir it all together and let it sit on your counter where it's warm for several days until it developes that distinctive sourdough aroma you're looking for. At this point it's ready to use or you can let it rest, covered, in the fridge. This is called the "sponge".
Before you use the sponge, you have to "set" it. Basically, that means that you're going to feed it so that it's ready to. And you'll want to have enough for your project plus one or two cups left over, to keep your starter going.
So how do you feed it? Add equal amounts of flour and water.
Here's my starter right out of the fridge, it's hard to see, but it's about the consistency of sour cream on the bottom with a thin layer of clear liquid on the surface. I sed this starter yesterday to make pancakes, I want to make bread tomorrow, so we're going to feed it today.
I have dumped in a cup each of flour and water.
I've stirred it up and here's the consistency I'm looking for. Feel free to keep it to the consistency you like by adjusting the amounts of flour and water. I prefer a thinner sponge for pancakes and a thicker one for bread. I'm going to let this sit out and it will grow and fill the pot.
If you don't bake regularly, store it covered in the fridge and feed it half a cup of flour and water each week. Remember that you will still have to set the sponge before you bake. If it turns hideous colors, developes a bad smell I would toss it out and start over. Mine will some times discolor to grey and I'll still use it, but if it's black, I toss it.
Just a couple notes, if it totally dries out you may be able to resusitate it by adding some warm water and letting it soak. You can also scrape down the crusty sides and even dried hard bits will come back to life with the yeast and enzyme action.