Building a Sourdough Starter:
Sourdough starter, also called levain or a mother, is a natural, living culture of wild yeasts. When you build a starter from scratch, the yeast mostly come from the air. The yeast will then multiply and proliferates when you create a comfortable environment for it.
A sourdough starter also contains bacteria that create lactic and acetic acids, which give sourdoughs their characteristic tart flavor. These acids will also develop, to some extent, in any dough that is allowed to proof slowly at a cool temperature, such as in the refrigerator overnight. This aging process is called retarding the dough.
Day 1: Combine 1 cup whole wheat flour with 1/2 cup cool, non-chlorinated water in a nonreactive container. Stir the flour and water together thoroughly making sure there are no dry flour clumps remaining. Cover the container loosely and allow the mixture to sit at room temperature (about 70°F) for 24 hours.
Day 2: Discard half the starter (about 1/2 cup), and add a scant 1 cup unbleached all-purpose flour, and 1/2 cup cool water if your house is warm, or lukewarm water if your house is cool. Note: You may or may not see any activity at all in the first 24 hours, and that’s ok!
Mix well, cover and allow the mixture to rest at room temperature for 24 hours.
Day 3: By this day you will likely see some bubbling activity in addition to some growth! It’s now time to start feeding your starter. You’ll want to do this twice a day, as evenly spaced as you can.
For each feeding, weigh out 4 ounces (a generous 1/2 cup), place it in a bowl and stir well. Discard any remaining starter.
Add a scant 1 cup unbleached all-purpose flour, and 1/2 cup water to the 4 ounces of starter. Mix well, cover and allow the mixture to sit at room temperature for about 12 hours. Repeat.
Day 4: Weigh out 4 ounces (a generous 1/2 cup), place it in a bowl and stir well. Discard any remaining starter. Repeat the remaining steps from day 3.
Day 5: Repeat the steps from day 4.
By the end of day 5, the starter should have at least doubled in volume. You’ll see lots of bubbles and the starter should have a tangy aroma. Note: If your starter hasn’t risen much and isn’t showing lots of bubbles, repeat discarding and feeding every 12 hours for as many additional days as needed, if necessary.
Once the starter is ready, give it one last feeding. Discard all but 4 ounces (a generous 1/2 cup), and feed as usual. Allow the starter to sit at room temperature for 6 to 8 hours; it should be active, with bubbles breaking the surface.
Remove however much starter you need for your recipe (no more than 8 ounces, about 1 cup); and transfer the remaining 4 ounces of starter to a permanent home such as a crock, jar, or anything else you would like to store it in long-term.
Feed this reserved starter with 1 cup flour and 1/2 cup water, and let it rest at room temperature for several hours, to get going, before refrigerating it. Store this starter in the refrigerator, and feed it regularly with a scant 1 cup flour and 1/2 cup water once a week.
Tips For Success:
It’s currently winter, and I live in a cold drafty house that doesn’t really go above 65. Not an ideal environment for a starter – they like it above the 68 degree range. If you don’t have a warm house, I would suggest using warmer water when feeding and also being creative on something to keep it warmer. Use a towel or blanket to wrap it, set by a heat register, store in your oven with the light on (I realize this is not great energy use), or use a heating pad.
It may take longer than expected
My starter took what seemed like forever. It was definitely close to two weeks of twice daily feedings to even look somewhat active. I almost gave up multiple times saying it’s not worth it and questioning why it wasn’t working. It didn’t rise or double like it said it should. I figured at that point I might as well put in the refrigerator and see what happens. It wasn’t until I switched to feeding it once a week and storing in the fridge, did it really start to show the right signs. As time went on, the better it got. So even if your starter doesn’t seem like it worked, it probably has, just give it time.
Use plastic containers when possible
Flour and water leftovers are like concrete. It’s a big pain to clean, so I started using plastic storage containers and mix in plastic when possible. I then let it dry out which causes it to crumble up and fall off the container.
Don’t overthink it
Use what ingredients you have. Don’t go out and buy bottled water or specialty flour. Use non-reactive containers you already have. There are going to be times where you think you’ve killed your starter, but I’ve learned that even if it looks desolate, starters can be resilient.
I was surprised one morning to open the container and find some fuzzies along the perimeter of the container. Of course you have a panic moment, but since the mold was not a scary color or in the starter itself, I moved my starter into a clean container. I see it as a sign it time to change out the storage to a clean one. As long your starter itself is not moldy, it should be fine to use.
Set a feeding schedule
Once your starter is going, the best method is to store it in the refrigerator, but you need to remember to feed it about once a week. I’ve found it doesn’t need to be exactly one week, but make sure you don’t forget about it. After feeding I usually leave it out for 4-5 hours to wake it up. Don’t forget to find uses for that discarded starter! There are lots of recipes for discard starter use online.