Domestic Yeast Starter:
1 1/2 cups warm (105F) water
1/2 tsp active dry yeast
3 1/2 cups all-purpose flour
Mix all the ingredients together in a medium bowl and mix in a Kitchen Aid mixer, with a dough hook, on medium speed for 1 to 2 minutes until a stiff, elastic batter is formed. Divide the starter into two equal pieces. Wrap one piece in oiled plastic wrap and freeze for later use. Place the remaining starter into an oiled glass bowl, cover, and allow to rise until triple in volume. This should take about 8 hours at room temperature or at least 14 hours in the refrigerator.
Wild Yeast Starter:
1 bunch organic grapes
2 cups flour
2 cups water
Allow the grapes to sit on your counter for two to three days to build up yeast cells on the surface of the grapes. Crush the grapes slightly, and measure out about 2 cups into a glass bowl. Add the flour and water. Mix with a wooden spoon until the batter has become thick and gooey. Cover the bowl with a clean towel and let it sit at room temperature overnight.
The next day, check the starter for bubbles of gas coming to the surface, a sure sign of fermentation. Be patient: This can take as long as 5 days in some environments. Once the starter has begun to ferment, strain out the grapes and “feed” the starter with a bit of flour and water. You can use the starter right away, or you can let it sit for another few days. The longer you let the starter ferment, the stronger the flavor of your bread will be; after about 4 days, chances are it will be too sour to eat.
If you aren’t ready to make bread right away, or if you’ve made enough starter for several loaves, you can freeze your starter and save it for later. Simply divide it into 1-cup portions, wrap each one in 2 layers of plastic, and put them in the freezer. To bring the starter back to life, let it sit in a glass bowl overnight at room temperature. When the yeasts “wake up,” the fermentation process will start again.