Why we ferment for 24 hours

Commercial yeast can proof a loaf in under two hours. Our starter takes a full day — and that is entirely the point.

Across roughly twenty-four hours, most of it at a cool temperature, wild yeast and lactic acid bacteria work slowly through the dough. They break down starches into simpler sugars, produce the acids that give sourdough its faint tang, and gradually build the structure that holds the loaf up. Flavour is a by-product of time. There is no way to add it at the end.

The long ferment does something else that matters more than taste. Those same bacteria begin breaking down gluten and phytic acid while the dough rests — work your digestion would otherwise have to do. It is a large part of why people who find fast commercial bread heavy often get on perfectly well with a properly fermented sourdough.

In practice it means every loaf starts the day before it is baked. The dough is mixed, folded a handful of times over the first few hours to build strength, then left to ferment slowly overnight. The next morning it is shaped, given a final proof, scored and baked.

It is slower, it is far less convenient, and it means we can only bake what we planned for a day in advance. That is the trade-off, and we would make it again every week.