Brandy is an alcoholic beverage produced by the distillation of wine with an alcohol content of between 35 – 60% by volume. It is mostly served as an after-dinner drink, but also popular in bars and nightclubs in many countries. It can also be produced by fruits other than grapes but is sold under different names, such as eaux-de-vie in France and schnapps in Germany. There are varying requirements held by countries in order to classify a drink as a brandy, but the most recognisable characteristic is that the distilled fruit alcohol is aged in oak containers for at least one year. The making of brandy is an effective way to salvage defective wines and production surpluses, ...view middle of the document...
The enhancement of flavours happens either by way of extraction of volatile oak compounds in newer barrels or through slow oxidative changes in older barrels from which little oak volatiles can be obtained (Lea, AGH et. al 2003, p.405). These volatile oak compounds (vanillin, eugenol and other aromatic compounds) are influenced by many factors such as the species of oak the barrel is made of, the source and climate of the wood, the time the oak wood was seasoned, the charring extent of the wood and the age and size of the barrel itself. Of course, the length of time the beverage is stored in the barrel too affects the taste and quality, leading to brandy having its own traditional quality rating depending on the years spent aging in oak.
Brewer’s years, Saccharomyces cerevisiae of the phylum Ascomycota, is the most common yeast associated with winemaking by fermenting sugars to alcohol and carbon dioxide via the overall equation:
C6H1206 2C2H5OH + 2CO2 +Energy
Glucose Ethyl alcohol
This equation does not show any of the intermediate steps and is the overall summary of a much more complicated series of reactions that result in the formation of alcohol (Carr, JG 1968). The S. cerevisiae yeast is of course not the only yeast responsible in the fermentation process, and interestingly not all these yeasts are found to be normal microorganisms inhabiting the grapes. Studies performed on yeasts present on grape surfaces showed that 50-75% of yeasts present were of the genus Kloeckera, with Candida, Kluvyeromyces and Hansenula being frequently present (Lea, AGH et. al 2003, p.26). The yeast S. cerevisiae was found to be absent on grape surfaces and it has been discovered that the species develops in wineries as a result of growth on winery equipment in a way that enables it to inoculate each new batch of wine with the same strain. Studies revealed that S. cerevisiae becomes the dominant yeast in the fermentation process, which is attributed to its lower sensitivity to ethanol...