Here is the most straightforward recipe to make a homemade sourdough starter.
Ingredients for Sourdough Starter
Flour – I prefer to use unbleached organic bread flour, but whole wheat flour, rye flour, and regular white flour are also great.
Bottled water, filtered water, boiled water, or tap water that has been left out overnight to allow the chlorine to evaporate.
Equipment for Sourdough Starter
A Glass Container – A wide-mouth quart-sized glass jar
Wooden spoon for stirring the mixture
Step-by-Step Instructions to make your own Sourdough Starter
Mix one cup of flour and one cup of lukewarm water in a glass jar.
Place the starter in a warm place in your house, preferably between 70-80 degrees (F).
Lightly cover the jar with a damp towel. Let sit for 24-hours.
Stir the starter with a wooden spoon, cover the jar loosely and let it rest for 24 hours.
You should see bubbles at this point and a slightly sour scent that is not unpleasant.
Stir your sourdough starter well using a wooden spoon.
Then discard half of the sourdough starter.
Add 1/2 cup flour and 1/2 cup water to the glass jar.
Stir until smooth, cover loosely, and let rest at room temperature for 24 hours.
Repeat the process each day until day 7. During this period, you should notice that the sourdough starter is getting increasingly bubbly and starting to increase in volume.
If it starts to bubble over, discard half of the starter. Then add 1/2 cup of flour and 1/2 cup of water.
After day seven, your starter should be ready to use in making sourdough bread or sourdough breadsticks.
It is ready when it doubles in size within 4-12 hours after feeding it, and the texture looks light and fluffy with plenty of bubbles on the surface and around the sides of the jar.
*Colder kitchens will take longer than warmer kitchens.
If you are not going to use it immediately, refrigerate until you are ready to bake bread. Just place your starter in the fridge with a lid on the jar, and then feed it weekly.
Each time you feed it, remove about half the starter from the jar and discard (or use in a sourdough recipe); add 1/2 cup of flour and 1/2 a cup of water to the jar.
Let the sourdough starter sit in a warm place for a couple of hours, and then return to the refrigerator.