Creating a Liquid Levain

A liquid levain begins simply as a mixture of flour and water. At The French Culinary Institute, the following guidelines are used to create a liquid levain.

• Wild yeast, present in the flour and in the environment, populates the mixture. It is stronger and more stable than commercial yeast, as well as more resistant to acidity. Starch in the mixture is broken down into sugar by the yeast and enzymes, resulting in alcohol and carbon dioxide, the by-products of fermentation.

  Starch > fructose/dextrose + alcohol + CO₂ (carbon dioxide)

• On the first day of starting the culture, use rye flour (the coarser the better) because rye flour contains more wild yeast. If you must use wheat flour, sift before mixing to incorporate more air.
• On Day 2, discard one-half of the total amount of the culture. Add water and flour to the mixture to continue the process.
• On Day 3, yeast activity begins in the culture. (One gram of flour contains 13,000 cells of wild yeast and about 320 cells of lactic bacteria.)
• Between Days 6 and 10, depending on the environment, acidity (lactic acid) starts to develop. This acidity inhibits bad bacteria (gray molds) that may be lurking.