True sourdough bread is unique. It’s nothing like the supermarket dollar loaf and if you’ve never had it, it’s unlikely you’ve ever eaten any bread quite like it. Sourdough is substantial and flavoursome and in its own right a work of art. It takes passion, chemistry, creativity and a can-do attitude to create a loaf that you’re truly proud of.
The heart of sourdough is the humble sourdough bug (also known as the starter, mother or levain). The bug has two simple ingredients: flour and water. However as soon as you mix these together, an enzyme naturally present in the flour (called amylase) is activated and goes to work breaking down the complex flour starches into sugars. Wild yeast and good bacteria both feed on these sugars during fermentation.
Wild yeast is a different strain of yeast than commercial, packaged yeast. It lives all around us in the air and on plants, grains, and fruits. There is some naturally present in the flour and more gets incorporated when you stir the flour and water together. The wild yeast is the leavening agent (it makes it rise) and also produces alcohol and carbon dioxide as a by-product a.k.a. extra flavour!
Also residing in our sourdough bug is a friendly, non-harmful bacteria called lactobacillus. Lactobacillus also feed on sugar and produce two kinds of acid as a by-product: lactic acid that gives the sourdough its mellow rich flavor and acetic acid that gives its tang and punch.
Many people usually intolerant to gluten find they can consume sourdough without any adverse effects. That’s because the amylase enzyme breaks down the gluten into sugars making it easily digestible.