Ensuring Proper Bulk Fermentation (or Bulk Proof)
A flour-and-water dough sits in a metal mixing bowl before the levain is mixed in
A dough made from flour and water is ready for the addition of the levain, which will mark the beginning of the bulk fermentation.
According to Trevor, bulk fermentation starts as soon as you add levain to a dough and ends when you divide or shape the dough. This stage is usually the longest period of fermentation, in which the majority of your dough’s flavor develops, gases accumulate in the dough, and—crucially—the gluten structure fully develops to trap those gases effectively.* In general, the majority of a dough’s fermentation occurs during bulk fermentation. Subsequent steps like the final rise and retarding represent a small fraction of the overall microbial fermentation and gluten development.
This idea assumes that you haven’t fully developed the gluten initially through machine mixing or aggressive, prolonged kneading. Instead, bakers often rely on time to fully develop a gluten matrix. Over time, enzymes, such as proteases, begin snipping strands of gluten into smaller pieces that are able to bond with one another. Chains of gluten elongate, and the network strengthens as more and more molecules stick together.
