Wine Chemistry and Biochemistry

358 M. Ugliano and P.A. Henschke

Ta b l e 8 D. 5A generalized chemical composition of wine made with indigenous yeasts

Concentration from indigenous

yeast fermentation wines relative

Wine composition to conventional wines

Residual sugar 1–5 g/L higher

Alcohol 0–1 vol.% lower

Glycerol 0–5 g/L higher

Titratable acidity 0–2 g/L higher

Acetic acid Up to twofold higher

Sulfur dioxide (total) Up to twofold lower

Acetaldehyde Up to twofold lower

Tannins Lower

modulate wine composition, thereby affecting most of the major constituents of

wine. The diversity of aroma compounds in wines also reflects the diversity of yeasts

in indigenous yeast fermentations. This fact is readily apparent in Fig 8D.12, which

compares Chardonnay wines made with indigenous yeasts with those made with

monocultures ofSaccharomyces cerevisiae, in the same juices (Varela et al. 2008).

This figure highlights the anecdotal observation that wines made withSaccha-

romyces cerevisiaeare more alike than those made with indigenous yeasts. That

is, in this experiment, wines made by inoculation were associated with the esters

Fig. 8D.12Association between fermentation esters and indigenous yeasts (Wild) andSaccha-
romyces cerevisiae(EC1118, D47/CY3079) (Varela et al., 2008)