Phase 9 (Acidity)
Acetic Acid Peak (Cool Fermentation)
Volatile acetic acid produced by heterofermentative bacteria in overly cool, stiff sourdough or overripe biga.
Origin & Trigger: While a slight acidic peak is desirable in rustic Pizza Integrale, a sharp vinegar smell in Pizza Napoletana indicates that the lievito madre or biga has been left too long and too cool.
Resulting acid: Acetic acid (acetate)
Molecular behavior: [HETEROFERMENTATIVE PHOSPHOKETOLASE] At cool temperatures (<20°C) and low water content, heterofermentative lactic acid bacteria produce increased amounts of volatile acetic acid (acetate) alongside lactic acid, which can make the gluten network of pizza dough brittle if overdone.