Designation (abbreviation BSA) for the process following alcoholic fermentation or, if applicable, already started during this process, especially in red wine production; see under malolactic fermentation.
Term for the conversion of malic acid into the milder-tasting lactic acid (Latin malum = apple, lac = milk), which plays an alternative role in the production of fruit juice, wine and sparkling wine(champagne, sparkling wine). The process is also called biological acid degradation (BSA), bacterial malic acid degradation, microbial acid degradation or apple-lactic acid fermentation, because carbon dioxide is also released. However, it is not actually a real fermentation, but was once thought to be. Around 1890, Dr. Hermann Müller-Thurgau (1850-1927), who was working in Geisenheim at the time, correctly suspected bacteria as the cause. Dr. Wenzel Seifert (1862-1942) was then able to identify the acid-degrading bacterium in 1903 at the Klosterneuburger Weinbauinstitut and named it "Micrococcus malolacticus".
It is a natural process that can take 10 to 40 days. It is started spontaneously from about 16 °Celsius by bacteria (Oenococcus oeni) that are already present or have been added. However, it can also be started by stirring from lees, by blending with a wine already in the BSA process or (which...
![]()
The Wine lexicon helps me to stay up to date and refresh my knowledge. Thank you for this Lexicon that will never end in terms of topicality! That's what makes it so exciting to visit more often.
Thorsten Rahn
Restaurantleiter, Sommelier, Weindozent und Autor; Dresden