Pressing whole cluster

Maceration increases the amino acid concentration in juice, resulting in an improved fermentation speed, which is often observed in practice. Macerated grapes also produce juice and wine that is richer in neutral polysaccharides (Table 13.10) and proteins than pressed whole clusters. Wines made from macerated grapes... 

Whole-cell biocatalysts, organic solvents and, 16 412-413 Whole cells, 3 669-671 Whole-cell systems ionic liquids in, 26 897 Whole cluster pressing in white wine, 26 311 Whole-wheat flour, 26 279, 283 Whole yeast vaccines, 26 488 Who needs it concept, 24 190 Wicking limit, heat pipe, 13 230 Wicks... 

Various techniques have been developed to handle fruit degraded by Bot-rytis cinerea. These include hand selection of deteriorated fruit, followed by whole-cluster pressing and segregation of press fractions, cryoextraction, as well as thermal processing (Ribereau-Gayon et al., 1976). 

Fig. 13.4. Whole-cluster pressing cycle in manual mode with a moving-head press (VasUn 22 VT). p to /06 = pressure level FIi to Ils = pressure step C = crumbling, drying or cake break-up...

Table 13.5. Evolution of must turbidity during whole-cluster pressing of Sauvignon grapes with a pneumatic Bucho" (22 hi) according to an automatic program (Figure 13.5)...

Variety Whole-cluster pressing Pre-fermentation maceration ... 

Chauvet et al. (1986) initially developed these techniques to improve the quality of juice intended for sweet winemaking (Section 14.2.4b), but they are also of interest for dry white winemaking. The process consists of cooling whole grape clusters in small crates for 20 hours or so in a walk-in freezer at a temperature of —2 to —3°C. Two phenomena—cryoselection and supraextraction—are at the origin of these changes in juice composition observed with respect to traditional pressing. 

---