Isovaleric Acid
Introduction
Isovaleric Acid, also known as 3-Methylbutanoic acid, is an organic compound with the formula (CH3)2CHCH2CO2H. The flavor and aroma are often described as rancid Parmesan, or foot odor. it is not to be confused with Butyric Acid. Brettanomyces can create isovaleric acid [1]. The compound generally takes a few months to produce by Brettanomyces. Isovaleric acid can also be produced by a bacteria that lives naturally on human skin and is responsible for foot odor called Staphylococcus epidermidis. It does so by degrading leucine, an amino acid present in sweat [2]. Leucine is also present in beer [3]. Brettanomyces also breaks down leucine present in beer into isovaleric acid (Controversial, but generally accepted) [4][5].
References
- ↑ Wikipedia article
- ↑ Ara K, Hama M, Akiba S, Koike K, Okisaka K, Hagura T, Kamiya T, Tomita F. Can J Microbiol. 2006 Apr.
- ↑ Hall, Nutfield, Redhill, Surrey. Amino Acid Esters in Beer. Brewing Research Foundation. July 14, 1980.
- ↑ Botha, Janita J. Sensory, chemical and consumer analysis of Brettanomyces spoilage in South African wines. March 2010. Pg 2, 13, 17, 18
- ↑ Oelofse, Adriaan. Investigating the role of Brettanomyces and Dekkera during winemaking. December 2008.