What by-product is created during alcoholic fermentation along with alcohol?

During alcoholic fermentation, yeast converts sugars into alcohol and carbon dioxide as by-products of the metabolic process. This reaction is crucial in the production of alcoholic beverages, as it not only generates ethanol, the type of alcohol that is consumable but also produces carbon dioxide, which can affect the texture and effervescence of certain drinks, such as sparkling wines and beers.

Carbon dioxide is a natural result of the fermentation process, and its production is a key indicator of active fermentation. The release of carbon dioxide can also influence the flavors and aromas in the final product depending on how it is managed during fermentation and aging.

While esters, acetic acid, and phenols can also be produced during fermentation and contribute to the complexity of wines and spirits, they are not the primary by-products associated explicitly with alcoholic fermentation like carbon dioxide is. Esters generally contribute to fruity aromas, acetic acid can lead to vinegar-like flavors when present in higher concentrations, and phenols can affect color and flavor but are more commonly associated with the grape or fruit material than the fermentation process itself.