Search results
Results from the WOW.Com Content Network
Diacetyl. Diacetyl is a chemical compound produced in yeast during fermentation and later reabsorbed. If the external ambient temperature during fermentation is lower than 26 °C (79 °F), diacetyl is absorbed insufficiently, resulting in a threshold of less than 0.04 mg/liter in beer, which gives the beer a mouthfeel similar to cream cheese. [1]
The yeast then absorbs the diacetyl, and reduces the ketone groups to form acetoin and 2,3-butanediol. [citation needed] Beer sometimes undergoes a "diacetyl rest", in which its temperature is raised slightly for two or three days after fermentation is complete, to allow the yeast to absorb the diacetyl it produced earlier in the fermentation ...
The primary role of yeast is to convert the sugars present (namely glucose) in the grape must into alcohol.The yeast accomplishes this by utilizing glucose through a series of metabolic pathways that, in the presence of oxygen, produces not only large amounts of energy for the cell but also many different intermediates that the cell needs to function.
A tartrate is a salt or ester of the organic compound tartaric acid, a dicarboxylic acid.The formula of the tartrate dianion is O − OC-CH(OH)-CH(OH)-COO − or C 4 H 4 O 6 2−. [1]The main forms of tartrates used commercially are pure crystalline tartaric acid used as an acidulant in non-alcoholic drinks and foods, cream of tartar used in baking, and Rochelle salt, commonly used in ...
Malolactic fermentation is most often performed as a secondary fermentation shortly after the end of the primary fermentation, but can sometimes run concurrently with it. The process is standard for most red wine production and common for some white grape varieties such as Chardonnay , where it can impart a "buttery" flavor from diacetyl , a ...
Industrial fermentation is the intentional use of fermentation in manufacturing processes. In addition to the mass production of fermented foods and drinks, industrial fermentation has widespread applications in chemical industry. Commodity chemicals, such as acetic acid, citric acid, and ethanol are made by fermentation. [1]
In biochemistry, mixed acid fermentation is the metabolic process by which a six-carbon sugar (e.g. glucose, C 6 H 12 O 6) is converted into a complex and variable mixture of acids. It is an anaerobic (non-oxygen-requiring) fermentation reaction that is common in bacteria .
In biochemistry, fermentation theory refers to the historical study of models of natural fermentation processes, especially alcoholic and lactic acid fermentation. Notable contributors to the theory include Justus Von Liebig and Louis Pasteur , the latter of whom developed a purely microbial basis for the fermentation process based on his ...