True sourdough is made with a starter of flour, water, and salt left to ferment for days to produce live cultures that create the bread's signature tang.
In contrast, industrial processes typically use the Chorleywood method, which mimics the taste and texture of sourdough with synthetic additives and vigorous kneading.
Although the industrial process creates a consistent, accessible product, it reduces the number of vitamins and minerals, making the bread less nutritional and harder to digest.
It's unclear whether Panera uses the Chorleywood method, but the bread’s ingredients are a far cry from sourdough's typical lineup of flour, water, salt, and starter.
Instead, the bread includes folic acid and "dough improvers" like microcrystalline cellulose, which are difficult or impossible for your body to process.