What is poolish?

A wet, equal-parts flour-water pre-ferment with a tiny amount of yeast — roughly 100% hydration, typically 0.1-0.3% baker's percentage yeast. Mixed the night before and rested 12-16 hours at room temperature until domed, bubbly, and slightly tart-smelling. The next day, the poolish goes into the final dough as a pre-fermented chunk of flour. The technique is traditionally attributed to 19th-century Polish bakers (hence the name), though food historians debate the true origin; either way it migrated through France into the modern artisan tradition. The point: a poolish ferment generates deep, slightly nutty flavor compounds the final dough never has time to develop on its own. It also produces better keeping quality — a poolish baguette stays fresh noticeably longer than a same-day version. Baguette and Neapolitan-style pizza both use poolish variants in the library.