1. First Day
Combine 4-ounces (1-cup) of whole-wheat flour with 4-ounces (1/2 cup) non-chlorinated cool water in a non-reactive container such as: glass, crockery, stainless steel, or food-grade plastic.
Whole grain flour is preferred at the beginning of the sourdough starter process. Whole grains contain more nutrients and sourdough-friendly microorganisms than all-purpose white flour.
It’s important to always feed the sourdough starter with non-chlorinated cool water.
Stir ingredients together well. Make certain there is no dry flour within the starter. Cover the container loosely and let the mixture sit at warm room temperature (about 70°F.) for 24 hours.
The colder the environment, the more slowly the sourdough starter will grow. If the normal temperature in your home is below 68°F, find a warmer spot to develop the starter.
Consider, setting the starter on top of a water heater, refrigerator, or another appliance that generates ambient heat. Or, set it near a heat source such as a baseboard heater.
2. Second Day
There may be no activity in the first 24 hours. Or, there may be a bit of growth and bubbling.
Discard 4-ounces or half the starter, and add to the remainder a scant 1-cup of unbleached all-purpose flour, and 4-ounces (1/2 cup) cool water if the kitchen is warm; or use lukewarm water if the kitchen is cold.
Mix well, cover, and let the starter rest at room temperature for the next 24 hours.
Save the discarded starter to bake bread, or for a sourdough pizza crust.
3. Third Day
By the third day there will be some bubbling, a fresh aroma and some expansion. It’s now time to begin two feeding daily, as evenly spaced as your schedule allows.
After 12 hours, the starter will have risen with lots of bubbles. Look for small bubbles on the surface.
The starter should have a tangy aroma – pleasingly acidic, but not overpowering.
For each feeding, weigh out 4-ounces starter; this will be a generous ½ cup, once it’s thoroughly stirred down. Discard the remaining 4-ounces of starter.
Why are we doing this? Unless you discard half the starter you’ll end up with the starter that ate Los Angeles-way too much starter. By keeping the starter volume the same helps balance the pH. And, keeping the volume down offers the yeast more food to eat each time it is fed. It’s not fighting with quite so many other little yeast cells to get enough to eat.
Add 4-ounces (a scant 1-cup) unbleached all-purpose flour, and 4-ounces (1/2 cup) water to the 4-ounces starter.
Mix the starter, flour, and water, cover, and let the mixture rest at room temperature for approximately 12 hours before repeating.
4. Fourth & Fifth Days.
Repeat two-a-day feeding on days 4, 5, and as many days as it takes for the starter to become very active.
After a week of consistent feeding, the starter should be ready to use in a sourdough bread recipe.
Several of my favorite books on sourdough are the following:
The Bread Bakers Apprentice: Mastering the Art of Extraordinary Bread by Paul Reinheart available on Amazon in print ISBN-10: 1580082688 and Kindle versions about $20.00.
The Bread Bible by Rose Levy Beranbaum also available on Amazon in print ISBN-10: 1580082688 and Kindle versions about $23.00.
Classic Sourdough Starter from King Arthur Flour Company, $8.95 this is a fresh live starter not dried.