At its most elementary, bread is merely flour, water, yeast and salt; yet if we take a deeper look, we find complex chemical transformations that turn lumps of wet dough into a food that throughout the ages has become synonymous with life itself. Familiarise yourself with the with the basic chemical, physical and functional properties of sourdough breadmaking and you too can turn out light, aromatic and rustic looking loaves that hold up against many bakeries.