Baking sourdough is a hobby many people have started. The advantages are three-fold. The bread lasts longer, because of microbes that make acids, preventing spoilage. Sourdough is also better for digestion. And it tastes better. It has been around for millennia, since the first bakers noticed that, after a couple of days, their gruel of rains and water started to bubble. Nearly all leavened bread in the world came from sourdough: from the French baguette to the famous San Francisco sourdough, developed at Boudin bakery in 1849. Sourdough doesn't have to be sour, and the term simply refers to any bread made from wild yeasts and bacteria.