Whiskey fermentation

The converted mash is pumped to a clean sterilised fermentor and the yeast inoculum is added. The set temperature range for whiskey fermentation of 72 hours is usually 17—21°C. At the beginning, the mash converted composition is approximately 80% sugars, mainly maltose and some (<1%) dextrose (primary conversion). The pH is adjusted to reduce initial bacterial growth. Grain neutral spidts are usually set at 27—29°C to expedite fermentation. Temperatures above 35°C inhibit yeast reproduction and promote rapid bacterial growth. Above 40°C actual yeast kill occurs. 

Source A product of whiskey fermentation (quoted, Verschueren, 1983). Isobutyl acetate was identified as a volatile constituent released by fresh coffee beans Coffea canephora variety Robust at different stages of ripeness (Mathieu et al, 1998). 

Grain Whiskey. Grain whiskey is an alcohoHc distiUate from a fermented wort derived from malted and unmalted barley and com, in varying proportions, and distiUed in a continuous patent stiU (Coffey). 

Malt Whiskey. Malt whiskey is an alcohoHc distiUate made from a fermented wort derived from malted barley only and distiUed in pot stiUs. It is the second fraction (heart of the mn) of the distiUation process. 

SourM sh. Sour mash is made with a lactic culture and not less than 20% stillage added back to the fermentor and fermented for at least 72 h. Spirits. Spirits are distilled spirits including all singular whiskeys, gin, brandy, mm, cordials, and others made by a distillation process for nonindustrial use. 

Irish Whiskey. Irish whiskeys are blends of grain and malt spirits three or more years of age that are produced in either the RepubHc of Ireland or Northern Ireland and comply with the respective laws regulating their manufacture. Since no peat is used in the malting process, Irish whiskey lacks the smokey character of Scotch. In the manufacturing process, the malt is soaked in water and milled to produce the wort. The fermentation usually takes about 60 hours. The first distillation in a pot stiU yields a 22—23% alcohol product. A second pot stiU distiUation produces a product that is 45—46% alcohol. This is foUowed by a third distiUation in another pot stiU to yield the Irish whiskey of about 68—70% alcohol. 

Whiskey. Whiskey refers to any alcohohc distiUate made from a fermented grain mash at less than 190° proof (95%) in such a manner that it possesses the taste, aroma, and characteristics generaUy attributed to whiskey. It is matured in new or used charred oak barrels. Whiskey can be further delineated by the cereal grains used and the maturation time and blending, if any. 

Bourbon. Bourbon, and also rye, wheat, malt, and rye malt whiskeys, are made from a fermented mash not less than 51% com, rye, wheat, malt, or rye malt, respectively. They are distiUed at not over 160° proof and matured at not more than 125° proof in new charred oak barrels and bottled at not less than 80° proof. If stored for less than four years, it must be declared on the label. 

Corn Whiskey. Com whiskey must be distiUed from a fermentable mash that contains at least 80% com and at not over 160° proof. It is usuaUy matured in new uncharred oak barrels or used oak barrels and bottled at not more than 125° proof. 

Yeast (qv) metabolize maltose and glucose sugars via the Embden-Meyerhof pathway to pymvate, and via acetaldehyde to ethanol. AH distiUers yeast strains can be expected to produce 6% (v/v) ethanol from a mash containing 11% (w/v) starch. Ethanol concentration up to 18% can be tolerated by some yeasts. Secondary products (congeners) arise during fermentation and are retained in the distiUation of whiskey. These include aldehydes, esters, and higher alcohols (fusel oHs). NaturaHy occurring lactic acid bacteria may simultaneously ferment within the mash and contribute to the whiskey flavor profile. 

Chemical Designations - Synonyms-. Alcohol Cologne spirit Denatured alcohol Ethanol Fermentation alcohol Grain alcohol Spirit Spirits of wine Chemical Formula CjHjOH. Observable Characteristics - Physical State (as normally shipped) Liquid Color Colorless Odor. Mild, pleasant Like wine or whiskey. (Denatured alcohol may be unpleasant). 

The production of ethyl alcohol for beverage, cosmetic, and pharmaceutical products is commonly accomplished by the natural process of fermentation. See Ethyl Alcohol Methyl Alcohol and Fermentation, Beer, wine, and whiskey production are extensively covered in the Foods and... 

Since malt is used as a source of liquefying and saccharifying enzymes in whiskey and grain spirits fermentations, and gibberellic acid increases the a- and /3-amylase content of malt, it became desirable to determine gibberellin residues in a distiller s feed by-product. 

The more concentrated forms of alcoholic drinks such as the spirits whiskey and brandy contain high concentrations of ethanol. These are produced by distillation after the fermentation is complete (Chapter 2, p. 20). 

DISTILLATION A heat-dependent process used to produce alcoholic beverages, such as whiskey, rum, and vodka. In this process, a fermented mash (of grains, vegetables, or fruits) is heated in a boiler, causing the alcohol to evaporate. The alcohol vapors are then collected and cooled in a condenser to produce the beverage. 

Our society now manufactures and consumes many distilled liquors. Scotch and bourbon whiskeys are made from beerlike preparations of grain. Rum is distilled from fermented molasses ... 

Ethanol is the alcohol found in beverages such as beer, wine, and whiskey it is produced by the fermentation of glucose in corn, barley, grapes, and so on ... 

PROP Light yellow-amber liquid. Pleasant to fruity odor. D 0.923-0.935 15.56° 47-53% of ethanol, by volume, flash p 80.0°F (CC). Made by distillation of fermented malted grains, e.g., corn, rye, or barley. After distillation, whiskey is aged in wooden containers for up to several years. The aging extracts such components as acids and esters from the wood and promotes oxidation of components of raw whiskey and some reactions between organic components to form new flavors. 

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