On food and cooking the science and lore of the kitchen ( PDFDrive ) 1455

bacteria cling. This greatly increases the
effective surface area of the wine, and
regularly exposes all parts of the liquid to
bothoxygenandbacteria.Theresultisaquick
fermentation that takes only a few days.
Finally, there is the “submerged culture”
method,inwhichfree-swimmingbacteriaare
supplied oxygen in the form of air that is
bubbled through the tank. This industrial
method converts the liquid’s alcohol into
aceticacidin24–48hours.

The intact acetic acid molecule, and the acid
dissociatedintoitsacetateandhydrogenions.
Only the intact molecule is volatile and
detectableinthenosebyitsdistinctivesmell.
Adding vinegar to an alkaline ingredient —
egg whites or baking soda, for example —


causestheaceticacidmoleculestodissociate,
anddiminishesitsaroma.
After Fermentation After fermentation,
nearly all vinegars are pasteurized at 150–
160ºF/65–70ºC to kill remaining bacteria of
all kinds, but especially the acetobacteria
themselves, which respond to the
disappearance of the alcohol by metabolizing
acetic acid to water and carbon dioxide and
thusweakeningthevinegar.Mostvinegarsare
agedforafewmonths,aperiodinwhichtheir

flavor becomes less harsh and more mellow,
thanksinparttothecombinationofaceticand
other acids with various compounds to form
new,lesspungent,oftenaromaticsubstances.
CommonKindsofVinegar

Cooks can choose among several different
kinds of vinegar. Though all have the basic
aroma and pungency of acetic acid, each is