Rivalling your nearest bakery, the best supermarket sourdough loaves still offer that signature tang and airy crumb. From Waitrose premium selection to Sainsbury’s own bloomer , which store-bought sourdough is best? I sliced my way through dozens of loaves to find out.

A naturally leavened bread, sourdough rises thanks to the activity of wild yeast rather than added raising agents. You know it’s a good loaf when the bread is soft, springy and the texture inside the bread is crumbly, with air pockets that are evenly spread throughout. Fermentation is key: when the baking process isn’t quite right, it can result in what bakers call ‘tunnelling,’ where overly large, uneven holes form inside the bread.

Swie Joo, head baker at The Palmerston , points out that “sourdough isn’t a legally protected term, so technically any bread can currently be called sourdough.” This means that the “rustic” looking loaf in your trolley might just be standard yeasted bread disguised with flavourings to mimic the tang of the real…