What is levain?

cold retard

A long, slow rise in the refrigerator (usually 12-72 hours). Slows fermentation dramatically — yeast activity drops by half for every ~18°F / 10°C cooler — while the bacterial side of a sourdough or pre-ferment continues to develop flavor at its own slower pace. The net effect: deeper sourness, more complex aromatics, and a more open crumb structure than the same dough fermented in one warm stretch. Cold retarding also has practical benefits beyond flavor. It splits a long bread project across two days, firms the dough enough to score cleanly, and lets cold-start oven techniques work without overproofing in the warm-up window. Cold-retarded doughs go into the oven straight from the fridge — no warming required.

stretch and fold

Grab one side of the dough in the bowl, stretch it up gently, fold it over the middle. Rotate the bowl a quarter turn and repeat — four passes around the bowl equals one set. Typically performed 3-4 times at 30-minute intervals during bulk fermentation. Stretch-and-fold replaces kneading for wet doughs (anything above ~70% hydration) where conventional kneading is impractical because the dough is too sticky to handle on a counter. The technique builds gluten in pulses rather than all at once: each fold realigns and tightens the gluten network without the surface tension getting in the way. The rests between sets let fermentation gas build up too, so the dough gets stronger AND lighter with each round. Standard for ciabatta, focaccia, country sourdough, and any high-hydration recipe.