Wines barrel-aged

Chip size, wood pieces vs wood chips, and the time the wood is in contact with the wine are all major factors affecting the volatiles released by the wood and hence the final volatiles content and the sensory characteristics of the wine. Barrel-aged wines were discriminated from oak chips treated wines from the same variety on the basis of their syringaldehyde and eugenol contents, while wine treated with small and big chips were discriminated on the basis of guaiacol (Arapitsas et al. 2004). 

Fig. 5.17. Development of protein stability in a dry Sauvignon Blanc wine barrel aged on total lees. This was assessed by the increase in turbidity after heating and by the quantity of bentonite necessary to achieve stability (Ledoux et al., 1992)...

Another problem raised by aging wines in oak is that of choosing the right barrels to suit the type of wine. Barrel aging must enable wines to develop their full character, yet remain in balance. If the oak/wine match is not perfect, there is a risk of acquiring a dominant woody character that overpowers the wine and dries it out rapidly. 

In barrel-aged red, white, and model wines, naturally occurring furfuryl alcohol decreased in concentration with time. In red wine, furfuryl ethyl ether was identified as a degradation product after 55 wk of storage. The average percentage decrease of furfuryl alcohol was 73% (Spillman et al, 1998). 

Source Furfuryl occurs naturally in yarrow, licorice, sesame seeds, clove flowers, and tea leaves (Duke, 1992). Also detected in barrel-aged red, white, and model wines. Concentrations ranged from 3.5 mg/L in white wine after 55 wk of aging to 9.6 mg/L after 11 wk of aging (Spillman et ah, 1998). Identified as one of 140 volatile constituents in used soybean oils collected from a processing plant that fried various beef, chicken, and veal products (Takeoka et al, 1996). 

Spillman, P.J., Pollnitz, A.P., Eiacopoulos, D., Pardon, K.H., and Sefton, M.A. Formation and degradation of furfuryl alcohol, 5-methylfurfuryl alcohol, vanillyl alcohol and their ethyl ethers in barrel-aged wines, / Agric. Food CAe/n., 46 (2) 657-663, 1998. 

Microoxygenation (MOX) is now widely applied for the maturation of red wines as an alternative to barrel aging. The proposed improvements in wine quality arising from MOX include color stabilization, removal of unwanted off-odors, and improvements... 

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. 

Many other odorous or volatile compounds, particularly furfural derivatives, nitrogenous compounds, and other phenols, have been identified in distilled beverages after barrel aging and not before (23), but their role is not yet clear. So far it appears that the components contributed by oak to wine and brandy probably are common to most mildly pleasant but not distinctively odorous hardwoods. They appear to be agreeably combined with a moderate tannin level and generally unaccompanied by any unpleasant tastes and odors in cooperage oak. 

The level of total phenolics in white wines varies from -100 to 300 mg/liter by the FC method. The levels will be on the low end of the scale if the must was subjected to oxidative treatment and the pressing was very light. Higher levels will be observed when harder pressing of the solids is utilized or if the wine was aged in new oak barrels. By spectral analysis, white wines have an average corrected absorbance of 4 AU, with a range of 1 to 11 AU. 

Chatonet, P. and Dubourdieu, D. (1998). Comparative study of the characteristics of American white oak (Quercus alba) and European oak (Querqus petraea and Q. robur) for production of barrels used in barrel aging of wines. Am. J. Enol. Vitic. 30, 61. 

FIGURE 5.12 Levels of (A) 2,2,6-trimethylcyclohexanone and (B) p-ionone in ruby port wine and oak barrels aged port wines. 

Little or no cooling was used during fermentation. Sulfur dioxide began to be employed at the end of the nineteenth century, as were pure yeast cultures. Wines were aged in tanks and barrels. Eastern wines are usually, but not always, easier to clarify than California wines. While some wine was bottled for sale, a great deal was sold in bulk to local bottlers or was sold directly to the consumer in barrels (50 gallons) or in demijohns (3-5 gallons). 

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