Oak barrels

White oak barrels of 190 liters (50 U.S. gallons) that have been previously used for bourbon maturation are often used a second and third time to age Canadian whisky. This used cooperage along with the higher proof distillation gives Canadians their characteristic light flavor compared to the heavy flavor of most bourbons aged in new charred oak barrels. 

The grain whiskeys used in Scotch blends are produced using com, rye, and barley malt and are distilled using a continuous multicolumn stiU at 180—186° proof (90—93%). Grain whiskeys are aged in used oak barrels of 190 Hter capacities. The used barrels are often purchased in the United States from bourbon distilleries. 

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. 

Gra.in Spirits. Grain spirits are neutral spirits from grain that are matured in used oak barrels and bottled at 80° proof or higher. The period of aging in oak may be declared on the botde. 

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. 

Brandy. Brandy is a distikate from fermented juice, mash, fmit wine, or fmit residues. It is distiked at less than 190° proof in such a manner as to produce the taste, aroma, and characteristics generaky attributed to brandy. Fmit brandy is distiked solely from the fermented juice or mash of whole, ripe fmit or from standard grape, citms, or other fmit wine. Brandy distiked exclusively from one variety of fmit must be so designated, except grape brandy which can be identified by the term brandy. Brandy must be matured a minimum of two years in oak barrels, otherwise it must be labeled immature. 

Brandies are distiked using batch or continuous systems. Variations of the pot stik are used in France. Elsewhere, both systems are used. The batch system yields a more flavorful product, whereas the continuous stik yields a lighter flavor. The first distikate using a pot stik is taken off at 60° proof. It is then redistiked to 148—160° proof. Brandy is matured in charred-oak barrels for two to eight years and bottled at 80° proof or higher. 

In the United States about 95% of the brandy comes from California. The first brandy was made in 1837 though it was not produced in quantity until 1867. Ak California brandy must be made from grapes grown and distiked in the state and aged a minimum of two years in oak barrels. 

Tequila is usuaky bottled at 80—86° proof. It is sold unaged as white tequila or it can be matured in oak barrels. Aging gives Tequila a golden color and a pleasant mekowness without altering its basic taste. 

Much work has been reported and summarized ia the Hterature on the matufing of various whiskeys ia charred or uncharred white-oak barrels (4—7). The early Hterature iadicates that total acids, aldehydes, esters, soHds, and color iacreased with aging time and that their concentrations were iaversely proportional to proof. Thus aging at higher proofs (over 127°) yields less color and flavor. The maximum allowable entry proof for straight whiskeys was iacreased from 110° to 125° by the U.S. Treasury Department ia 1962. 

In the US, more than 80% of caramel is used to color drinks such as colas and beers. Another important application is the coloring of blended whiskeys produced by mixing straight whiskeys with neutral spirits. The addition of neutral spirits to the straight whiskey produces a loss of color that can be compensated by the addition of caramel. Straight whiskeys are colored during aging for 2 yr in freshly charred oak barrels and contain furfural and 5-HMF in a ratio of 2 to 2.6 1, while the ratio... 

Benzoic aldehydes mainly cover syringaldehyde and vanillin. Natural vanilla is prepared from the seeds (beans) of Vanilla planifolia, which may contain about 21 mg/ 100 g FW total phenols, including the major components vanillin (19.4 mg/100 g FW), 4-hydroxybenzaldehyde (1 mg/100 g FW), and vanillic acid (0.4 mg/100 g FW) (Clifford 2000b). In mango, vanillin has been found as free as well as vanillyl glu-coside (Sakho and others 1997). It has also been found in lychees (Ong and Acree 1998) and wines (Moreno and others 2007). For analysis of both brandy and wine aged in oak barrels, the limits of detection were found to be 27.5, 14.25, 14.75, and... 

Moreno NJ, Marco AG and Azpilicueta CA. 2007. Influence of wine turbidity on the accumulation of volatile compounds from the oak barrel. J Agric Food Chem 55(15) 6244-6251. 

RELATIVE AMOUNT OF EIGHT ANTHOCYANINS IN FOUR TEMPRANILLO WINES (VINTAGE 1999) DURING THEIR AGEING IN OAK BARRELS (O) OR IN STAINLESS STEEL TANKS (S)... 

Apetrei, C., Apetrei, 1. M., Nevares, L, Del Alamo, M., Parra, V., Rodriguez-Mendez, M. L., and De Saja, J. A. (2007). Using an e-tongue based on voltammetric electrodes to discriminate among red wines aged in oak barrels or aged using alternative methods. Electrochhn. Acta 52(7), 2588-2594. 

Parra, V., Arrieta, A. A., Fernandez-Escudero, J. A., Iniguez, M., De Saja, J. A., and Rodriguez-Mendez, M. L. (2006a). Monitoring of the ageing of red wines in oak barrels by means of an hybrid electronic tongue. Anal. Chim. Acta 563(1-2), 229-237. 

Ortega-Heras, M., Rivero-Perez, M. D., Perez-Magarino, S., Gonzalez-Huerta, C., and Gon-zalez-Sanjose, M. L. (2008). Changes in the volatile composition of red wines during aging in oak barrels due to microoxygenation treatment applied before malolactic fermentation. 

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