Vinegar Fermentation

• Main Author: Tan, San Chiang
• Other Authors: Paul W. Wilson
• Format: Others
• Language: en
• Published: LSU 2005
• Subjects: Food Science
• Online Access: http://etd.lsu.edu/docs/available/etd-11092005-152334/

Traditionally, the manufacture of vinegar provided a means of utilizing a large proportion of the cull fruit from apple-packing establishments and the waste from apple processing facilities. Most vinegar is now produced from distilled grain alcohol. Vinegar may be defined as a condiment made from various sugary and starchy materials by alcoholic and subsequent acetic fermentation. The vinegar bacteria, also called acetic acid bacteria, are members of the genus Acetobacter and characterized by their ability to convert ethyl alcohol (C2H5OH) into acetic acid (CH3CO2H) by oxidation. Vinegar can be produced from various raw materials like distilled alcohol, wine, rice wine and any kind alcoholic solution by several major production techniques for making vinegar such as the Orleans process, generator process and submerged acetification process. The Orleans process consists of wood barrels filled with alcohol liquid fermented for about 1 to 3 months at 70ºF to 85ºF (21°C to 29°C). After fermentation, 1/4 to 1/3 of the vinegar is then drawn off for bottling and an equivalent amount of alcoholic liquid added. The generator process was introduced by Schutzenbach in 1823. Non compacting material is filled in the large upright wood tanks above a perforated wood grating floor. Re-circulated fermenting liquid trickles over packing material toward the bottom while air moves from the bottom inlets toward the top. The recirculation process takes about 3 to 7 days after which 2/3 of the final vinegar product is withdrawn from the tank and new alcohol solution is added. In 1955, Hromatka reported on a new method of making vinegar using submerged acetification. In this process, supply air is forced into the alcohol liquid in the tank and the material is fermented at 86°F (30°C). At the end of every cycle, 1/3 of the liquid is discharged as final product, replaced with mash containing fresh alcohol solution and a new fermentation cycle begins. The aim in the present study is to identify quality and microbial differences between the generator process and submerged acetification and to characterize the species of vinegar bacteria used in acetification.