Viticulture and Wine Science - Horticulture: Plants for People and Places - page 243

Table 7.6 Concentration ranges of the major chemical constituents of dry wine
Constituent group Example Concentration range

Major alcohols Ethanol 8-15 % (v/v)

Glycerol 0.3-1.4 % (v/v)

Organic acids Tartaric acid 1-6 g/L

Malic acid tr—8 g/L

Lactic acid tr—5 g/L

Succinic acid tr—1.5 g/L

Acetic acid tr—1.5 g/L

Sugars Glucose tr—5 g/L

Fructose tr—5 g/L

Phenolic compounds Flavonoids tr—4 g/L

Anthocyanins a 0-0.5 g/L

Non-flavonoids 0.1-0.5 g/L

Cations Potassium 0.5-2 g/L

tr trace
a Anthocyanins are a sub-group of flavonoids

of all wine styles. Early completion of microbial wine fermentations is particularly
advantageous in wineries located in cooler climates, in those wineries with limited
facilities for temperature control of fermentation, and when the demands of wine-
making require early blending decisions to be made, such as in the preparation of
sparkling wine bases. Concurrent inoculation of MLF and yeast starter cultures or
inoculation prior to the completion of alcoholic fermentation is now a common
industry practise (Schmidtke et al. 2010 )

Wine Chemistry

The major components of dry table wines can be broadly categorised by the general
groups outlined in Table 7.6 . Of course the exact composition of wine will depend
on a multitude of factors such as grape variety, vintage conditions, wine produc-
tion techniques and wine age. Furthermore, the less concentrated components of
wine that are at mg/L concentrations and below, can have a dramatic impact on the
sensory appeal and hence commercial success of the wine. This is particularly the
case for certain aroma compounds in red and white wines. This section will provide
a broad description of the types and sources of compounds contributing to wine
aroma, mouth-feel and red wine colour. This section will also outline the methods
utilised to ensure that a wine will remain fault free for a suitable period of aging in
the bottle, without the formation of colloidal material, precipitates or detrimental
oxidation characters.
The aroma of a wine is an important feature of the finished commercial product.
Certain wine styles have pronounced aromas associated with the grape variety and
are commonly termed 'varietal' styles (such as Sauvignon Blanc), whilst others are
more dominated by wine production aromas (i.e., yeast-derived and/or oak-derived)