So, creating a Pure natural leaven or starter, using only flour, water and the wild yeast that is floating in the air and clinging, dormant, to unbleached flour.
I've spoken of Maple my natural leaven that was born in 2005 and has flourished ever since giving rise to many hundreds of loaves. This is how it is done:
The method I used, back in 2005 to create Maple, is the “high hydration” method, also known as the “poolish” method where a slurry of flour and water is mixed together, roughly 1:1 flour to water, with flour added as necessary to achieve a pancake batter consistency. Higher hydration creates a more amenable environment for fermentation than lower hydration. One discerns fermentation by observing bubbles in the batter, increasing volume of the batter and a tangy smell after 2-4 days.
Mix 1/3 cup white unbleached AP flour with 1/3 cup filtered water in a small see-through plastic container, blend (I use a plastic chop stick) adding ½ teaspoons of flour if needed until it is the consistency of pancake batter, scrape down the sides with your chop stick and let it to sit uncovered on your counter top for 4 hours then seal with plastic wrap.
The next day, 24 hours later more or less, observe your batter, if any water has risen to the top pour it off then stir the batter vigorously with the chop stick. You are accomplishing two important things. First you are aerating the mixture and secondly redistributing any wild yeast that has begun to take root. Recover with plastic wrap and let it sit for another 24 hours.
By day three you should be seeing some activity, maybe just small bubbles, maybe dramatic volume increase.
If you are seeing small bubbles but there is no dramatic change in volume then add 1 heaping tablespoon of flour, stir vigorously with the chop stick recover and let it sit another day. After 24 hours there should be discernable activity and you can proceed to developing your starter. If not then it is not meant to be, throw it out and start a new batch.
If the mixture has grown considerably -- 1 ½ to 2 times, has lots of larger bubbles and is giving off an unmistakable yeasty smell then you know that you have an active colony of wild yeast in the batter. Now we start the process of developing the starter.
Stir it down, discard ½ of the stirred down batter
and add 1/2 cup flour and 1/3 cup water to what is left. Stir vigorously. Now that the yeast is alive and active we are adding less water relative to flour. We are now looking for stiffer dough, with a consistency more like peanut butter. Recover with plastic wrap and let it sit over night. 24 hours later it should have grown dramatically.
Stir it down with the chop stick, discard ¾ of the stirred down dough and add 1/3 cup water and 1/2 cup flour (adding small amounts of flour or water as needed to achieve the peanut butter consistency) to what is left. Stir vigorously. Recover with plastic wrap and let it sit over night. Again, 24 hours later it should have grown dramatically. Stir it down with the chop stick, discard 9/10 of the stirred down dough and add 1/3 cup water and 1/2 cup flour (adding small amounts of flour or water as needed to achieve that peanut butter consistency) to the small amount left. Notice that each day we discard more of stirred down starter while adding the same amount of flour and water. That 1/10 of remaining starter has active wild yeast in it. Flour is its food source; water gives it a moist medium to flourish in. To create a vigorous starter that you can bake with you need to concentrate and ‘train’ your yeast to quickly multiply and populate any fresh flour that is added to it. This process is called refreshing: adding a disproportionate amount of flour (1/3 cup, and water of course) to the relatively small amount, 1/10, of the stir down that is left.
Continue the daily refreshing until your starter at the minimum doubles with in 8 hours. At that point you will have a ‘vigorous starter’, one that will leaven bread.
As you continue the refreshing process the starter becomes more and more vigorous.
Here is a refreshment done at 8:31 AM:
11 Hours later, this is not vigorous enough
After a couple more refreshing cyles:
A mere 5 hours later:
Now you have a starter that will leaven bread:
By the way, if you are in the Washington Dc area pick up a copy of Flavor magazine available for sale at local Gourmet stores. Check out the article "Taming the wild yeast" It shows me, Pedro Pan and my bread in all its glory! Otherwise check out the Magazine website in July when the article will be posted on the site: http://flavormagazinevirginia.com/
