Oenococcus oeni is a type of bacteria commonly found in wine. It plays a crucial role in the winemaking process, particularly during malolactic fermentation, where it converts malic acid into lactic acid. This process helps to soften the taste of wine and can enhance its flavor profile. This bacterium is known for its ability to thrive in the acidic environment of wine. Oenococcus oeni is often used in the production of red wines and some white wines, contributing to the overall stability and complexity of the final product. Its presence is essential for many winemakers aiming for specific taste characteristics.