Tweet A simple mixture of flour and water--a 6,000-year-old discovery in ancient Egypt--is all it takes to create sourdough starter. Left at room temperature, wild yeasts and the bacteria, Lactobacillus, from the grain and the air jumpstart the process of fermentation, which gives the dough its sour flavor. After "feeding" it with more flour and water for about a week, the starter can be used in place of yeast in bread and other recipes. The starter may be kept alive for an indeterminate period--many trace back over 160 years. Some sourdough enthusiasts claim a range of health benefits, from treating disease to boosting mood. While sourdough bread may not live up to all of these claims, research reveals some advantages. The fermentation and long rising time appears to help break down starches, proteins, gluten, and phytates in grains, making them easier to digest, as well as boosting nutrient availability. The absorption rate of starches is slowed...