As the name suggest, sourdough is nothing more than a dough which is sour. But why is it sour if two basic ingredients inside are only flour of some kind and water? And why is it bubbly and has a funky smell? Neither flour not water is sour, bubbly or have funky smell and mixing two together doesn’t result in any chemical reaction.
The answer is both very simple and very complex at the same time. Flour, like everything else in this world, contains many microorganisms which are hibernating on the surface of flour particles. Once one adds some water to flour, these microorganisms wake up and start eating, multiplying and, well, simply living their life. Let’s take a look at who they are and what exactly are they doing inside our sourdough.