A sourdough starter (sometimes called a ‘sourdough mother’) is simply flour mixed with water which is left to naturally ferment. This fermentation is a process where the flour is broken down by the action of microorganisms – harmless bacteria and wild yeasts that are naturally present on the grains and in the air and all around us.
A portion of starter is added to the ingredients for each loaf. The action of the microbes on the grains of flour, releases bubbles of carbon dioxide, which, trapped by the dough, makes the bread ‘rise’. Usefully this process also enables the flour to release significantly more nutrients, become more digestible, tastier and with a better texture than the bread we have sadly become used to. Additionally, sourdough fermentation degrades the gluten (a protein in grains) which means that for some people who have a sensitivity to gluten, long fermented sourdough breads are easier to eat.