pH

A scale that measures how acidic something is. Lower numbers mean more acidic, and each whole step is about ten times stronger. Sourdough bread commonly lands somewhere around pH 3.8 to 4.5, while a ripe starter usually reads lower than the finished bread. pH tells you how intense the acidity is at that moment, not the total amount of acid present.

By Henry Hunter · Updated October 1, 2026

Henry's notes from the bench

• You don't need a pH meter to bake great sourdough. Your nose and the starter's rise tell you most of what you need. A meter's a fun tool once you want to track consistency.