overfermenting

Overfermenting is the condition in which a fermentation process continues past its optimal point, producing changes that are no longer desirable for the intended product. It can occur with yeast or bacteria used in foods and beverages and may alter flavor, aroma, texture, and acidity.

In bread, overfermentation weakens gluten structure, causing a collapsed rise, coarse crumb, and a strong sour or alcoholic aroma. In dairy and yogurt, extended fermentation can yield overly tangy flavors and possible separation of liquids. In alcoholic beverages, continued fermentation can create off-flavors such as solvent notes or excessive dryness.

Causes include prolonged exposure to heat, excessive time, insufficiently controlled temperature, and the presence of contaminating wild strains or insufficiently active starter cultures. Substrate depletion or changes in pH can also drive a continued metabolism that diverts from the intended profile.

Prevention focuses on monitoring fermentation progress, controlling temperature and duration, and using reliable starters. When overfermentation is detected, cooling or stopping fermentation, adjusting storage conditions, or isolating the process can help preserve quality.