Carbonic maceration wines

Enzyme systems in the grape cells, particularly alcohol dehydrogenase, cause the phenomena that give carbonic maceration wines their specific character. 

The description of the specific aromas of carbonic maceration wines is confronted by the well-known difficulties of tasting vocabulary. According to experts, carbonic maceration wines have a dominant fruitiness with notes of cherry, plum and fruit pit, whereas traditionally made wines have a dominant vinosity with notes of wood, resin and licorice. In addition, the various aromatic components are more harmoniously blended in carbonic maceration wines. 

Fig. 1. An amplified outline scheme of the making of various wiaes, alternative products, by-products, and associated wastes (23). Ovals = raw materials, sources rectangles = wines hexagon = alternative products (decreasing wine yield) diamond = wastes. To avoid some complexities, eg, all the wine vinegar and all carbonic maceration are indicated as red. This is usual, but not necessarily tme. Similarly, malolactic fermentation is desired in some white wines. FW = finished wine and always involves clarification and stabilization, as in 8, 11, 12, 13, 14, 15, 33, 34, followed by 39, 41, 42. It may or may not include maturation (38) or botde age (40), as indicated for usual styles. Stillage and lees may be treated to recover potassium bitartrate as a by-product. Pomace may also yield red pigment, seed oil, seed tannin, and wine spidts as by-products. Sweet wines are the result of either arresting fermentation at an incomplete stage (by fortification, refrigeration, or other means of yeast inactivation) or addition of juice or concentrate.

Compared with wines produced by conventional techniques, carbonic maceration produces wines of distinctive character of superior quality possessing a harmonious balance. It can be used to generate a wide range of wines (red as well as rose), to be drunk young or aged. 

Caxignan tanks (110 hi) of conventionally produced (CP) wines vinified with crushed grape harvest and carbonic maceration (CM) wines. After pressing F, free-run juice, P, pressing juice FP, assembly of F and P. Total potential alcohol = produced alcohol + alcohol corresponding to the residual sugars (Andre et al, 1967). 

FIGURE 1.3 Sensory profiles of three carbonic maceration (CM) wines from Shiraz in 1995, after 16 months. (Figure from Flanzy et al., 2001. Reproduced with the permission of the Editor.)... 

Carroll, D. E. (1986). Effects of carbonic maceration on chemical, physical and sensory characteristics of muscadine wines. J. Food Sci. 51,1195-1196. 

Etievant, P., Issanchou, S., Marie, S., Ducruet, V., and Flanzy, C. (1989). Sensory impact of volatile phenols on red wine aroma Influence of carbonic maceration and time storage. Sci. Aliments 9,19-33. 

Fuleki, T. (1974). Application of carbonic maceration to change the bouquet and flavor characteristics of red table wines made from concord grapes. /. Inst. Can. Sci. Technol. Aliment. 7, 269-273. 

Salinas, M. R., Alonso, G. L., Navarro, G., Pardo, F., Jimeno, ]., and Huerta, M. D. (1996). Evolution of the aromatic composition of wines undergoing carbonic maceration under different aging conditions. Am. ]. Enol. Viticult. 47,134—144. 

In the past decade, some North Coast wineries have experimented with a completely anaerobic fermentation technique known as carbonic maceration. In this system, whole grapes are placed in a vat and fermentation is allowed to start. Since there is no pumping over or aeration, the fermentation proceeds very slowly under a blanket of carbon dioxide. The fermentation relies upon the intercellular production of ethanol to kill the skin cells and release the color and tannins. The results are claimed to be wines with a special bouquet, earlier maturity, slightly more alcohol, and a softer taste. They are easily recognizable by their special bouquet. Although popular in France, where they are drunk very young, they have not gained widespread acceptance with the North Coast wineries. 

Ricardo da Silva, J. M., Cheynier, V, Samson, A., Bourzeix, M. (1993). Effect of pomace contact, carbonic maceration and hyperoxidation on the procyanidin composition of Grenache blanc wines. Am. J. Enol. Vitic., 44, 168-172. 

Ethanol in wine is mainly produced by the alcoholic fermentation of sugar in must. However, grape cells are also capable of forming small quantities, mainly under anaerobic conditions (carbonic maceration see Volume 1, Section 12.9.3). The appearance of traces of ethanol in grapes results from alcohol dehydrogenase activity, which acts as a marker for ripeness. 

Novello wine (or noveau) is obtained from the intracellular fermentation of the entire grapes placed in special stainless steel vats in absence of oxygen and saturated of carbon dioxide. This process is technically called carbonic maceration. The wine has normally a fiuity bouquet, a clean red colour and a fresh taste. 

Finally, fermentation with carbonic maceration takes advantage of the special aromatic qualities produced by fermenting whole grapes under anaerobic conditions (Section 12.9). This special fermentation gives these wines specific organoleptic characters. 

Table 12.19 compares free run and press juice composition for traditional (crushed grapes) and carbonic maceration winemaking. In carbonic maceration press wines, the alcohol content is higher (caused by ethanol fixation) and the acidity lower (due to malic acid degradation). These wines also have lower concentration of phenolic componnds and other extracted components their dissolntion is diminished. 

Table 12.19. Run-off and press wine analysis comparing traditional winemaking with carbonic maceration (Flanzy et al., 1987)...

During the second fermentation phase, the complete transformation of sugar into alcohol is generally very quick. It is carried out at 18-20°C to preserve aroma components. Afterwards, the favorable conditions permit the easy initiation of malolactic fermentation. Despite the existence of two distinct phases, carbonic maceration requires less time than traditional winemaking. This method is therefore well adapted for wines that are quickly put on the market. 

Table 12.20 (Flanzy et al., 1987) compares the composition of traditionally made wines (crushed grapes) and wines having nndergone carbonic maceration (effected at 25 and 35°C). The importance of temperature in anaerobic metabolism is shown. At 35°C, this techniqne permits the same tannic structure as traditional winemaking. In general, density and dry extract, fixed acidity and phenolic compound concentrations are lower with carbonic...

The strnctnral difference of a wine having nndergone carbonic maceration, with respect to a traditionally made wine, as pointed out by laboratory analysis, is reflected in its organoleptic characters. Carbonic maceration produces supple, round, smooth and full wines. For this reason, they are often used in blends to improve wine quality. However, this positive characteristic in certain situations can be negative in others wines... 

Carbonic maceration is certainly most interesting from an aromatic viewpoint. It produces wines with a unique aroma. Some have accused this technique of producing uniform wines and of masking the aromas of quality varieties (Rib6reau-Gayon et al, 1976). Other authors (Flanzy et al., 1987) find that the aromas of certain varieties (Muscat and Syrah are intensified. This technique has also been observed to increase the aromatic intensity of relatively neutral varietal wines (Aramon, Carignan). 

Among the variety of methods for making rose wines, immediate pressing and drawing off are the most common. Carbonic maceration (Section 12.9) is not very widely used, but it produces interesting, complex aromas in full-bodied rose wines (Adre et al., 1980). However, it frequently results in wines that are too deep in color for a classic rose, even if the anaerobic phase is short and the temperature is controlled (35 C for 36 hours or 25°C for 48 hours), so they must be blended with lighter-colored wines. 

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