Lactic Acid

The main acid made by the bacteria in a sourdough starter. It has a mild, creamy, yogurt-like sourness. Warmer, wetter fermentation tends to favor lactic acid, which is why a liquid starter kept on the warm side usually tastes milder and rounder than a stiff one kept cool.

By Henry Hunter · Updated October 1, 2026

Henry's notes from the bench

• If your family says your sourdough's too sour, keep the starter and dough warmer and a little wetter. You'll tilt things toward the softer lactic side.