Maceration time

Fetuses are sorted by weight so that the maceration time can be controlled according to the size of the fetus. 

Femandez-Zurbano, P. et al.. Effects of maceration time and pectolytic enzymes added during maceration on the phenolic composition of must. J. Food Sci. Technol. Int. 5, 319, 1999. 

Table 6A.1 Average biogenic amine concentrations (mg/L) for different levels of vintage, pectolytic enzymes, aging on lees, maceration time and bacteria inoculation (from Martin-Alvarez et al. 2006, with permission)... 

Gambuti, A., Strollo, D., Ugliano, M., Lecce, L., Moio, L. (2004). tra s-Resveratrol, quercetin, (-t)-catechin, and (-)-epicatechin content in south italian monovaiietal wines Relationship with maceration time and marc pressing during winemaking. J. Agric. Food Chem., 52, 5747-5751. 

St. Amand GS, St. Amand W (1951) Shortening maceration time for AUzarin red S preparations. Stain Technol 26 271. 

Polyphenolics are important constituents of grapes in determining the color, taste, and body of wines. Unlike other alcoholic beverages, red wine, which is obtained after about 10 days of maceration, contains phenolic compounds in substantial concentrations of up to 4 g L . Due to the lower maceration time, white and rose wines contain about a tenth of the polyphenol levels of red wines [1]. Among these compounds, stilbenoids constitute an important subclass, whose overall levels can reach over 100 mg in red wine. Resveratrol is one of the major stilbenoids of red wine with numerous promising biological activities. 

Hernandez-Orte, P., A. Guitart, V. Ferreira, J. Garcia, and J. Cacho. 1998. Effect of maceration time and the addition of enzymes on the amino acid composition of musts and wines and its influence on wine aroma. Food Sci. Tech. Int. 4 407-418. 

Today, most red wines are fermented in tanks that can be closed when the carbon dioxide release rate falls below a certain level. The complete protection from air permits maceration times to be prolonged, almost as long as desired. The tank can be hermetically sealed by a water-filled tank vent (Figure 12.5) or simply closed by placing a cover on the tank hatch. In the latter case, the CO2 which covers the upper part of the tank disappears over time and the protection is not permanent. The tank should therefore be completely filled with wine or a slight pumping-over operation should be carried out twice a day to immerse the aerobic germs. 

The dissolution of phenolic compounds from solids into fermenting must varies according to maceration time, but no proportional relationship between maceration time and phenolic compound concentration exists. Color intensity has even been observed to diminish after an initial increase during the first 8-10 days (Ferre, 1958 Sudraud,... 

Fig. 12.9. Color intensity and phenolic compound concentration evolution of red wines according to maceration time (Ribereau-Gayon et al 1970). Color intensity is defined as the sum of the optical densities at 420 and 520 nm at 1 mm thickness, (Cl = OD 420 + OD 520). Total phenolic compounds are determined by the permanganate index...

Evidently, these notions pertaining to the evolution of color and anthocyanins in terms of maceration time primarily concern new wines—anthocyanins are in fact the essential elements of their color. As wine matures, the role of tannins becomes increasingly important. Extended vatting times produce more colored wines, even if the resulting new wines initially appear to confirm the contrary. 

Both the average and maximum temperature affect extraction. The results of a laboratory experiment in Table 12.6 indicate the simultaneous influence of maceration time and temperature. When maceration is prolonged, an elevated temperature... 

By taking into account the previously mentioned notions, general red winemaking principals can be improved for the better control of maceration time and intensity. 

Maceration times vary from 12 to 20 hours, depending on the winery. At controlled temperatures (10-15°C) and in the absence of oxygen, this time period seems to permit a suitable extraction of aromatic compounds from the skins without the risk of significant dissolution of phenolic compounds. 

The tannin/anthocyanin ratio permits the two winemaking methods (direct pressing and drawing off) to be differentiated. This ratio diminishes as the maceration time increases and it is higher when the grapes are directly pressed. 

The first steps of winemaking with maceration consist of moderately crushing and destemming the grapes. The grapes are then transferred to the tank and sulfited at 5-10 g/hl. The fermentation temperature is set at approximately 30°C to favor maceration. Maceration times vary from 2 to 8 days, if the fortification occurs after must separation. In this case, the fermentation speed should be reduced beforehand. Wines are macerated for 8 to 15 days when continuing the maceration after fortification. 

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