ON CHEMICAL COMPOSITION AND QUALITY OF THE RESULTING WINE

There are many manipulations a winemaker can perform in preparation for and during fermentation that alter chemical composition, and therefore the quality of the resulting wine. Two major components of juice and must that are critical in providing optimal gustatory balance in a finished wine include acidity and sugar. Winemakers in cool climate regions, where grapes do not always have the opportunity to reach full maturity, are faced with the problem of low sugar content and higher acidity. Other complications commonly encountered in the traditional vinification of red wine exclusively, is the extraction of pigment compounds that are capable of providing an intensely rich coloured red wine.

Various manipulation techniques are under investigation to identify efficient and economical methods altering these components. Although these techniques might aid in the correction and balance of these constituents in the juice or must, one must be aware of its effects on the many components that determine the complexity of the juice and more importantly the resulting wine. The significance and implications of various te

1 a. Bonorden, W. R., Nagel, C.W. and J.R. Powers. The Adjustment of High pH / High Titratable Acidity Wines by Ion Exchange. Am. J. Enol. Vitic. 37:143-148. (1986).

A) TECHNIQUES USED IN THE CONCENTRATION OF SUGARS

Because of the wide variability of situations and climates, it happens that the state of maturity of grapes is insufficient to produce a well balanced wine. Winemakers can make adjustments within well-defined limits, with the object of alleviating the deficiencies of the vintage. It is important to emphasize that manipulation procedures never completely compensate, as the other many components are affected.

Obvious drawbacks that accompany the use of calcium carbonate, is the increase in the calcium in the resulting wine, which consequently increases the probability of tartaric precipitations later in the bottle. When using methods that apply only to tartaric acid, the final wine might contain such low amounts of acidity, that gustatory balance is disturbed. Therefore, neutralization of a grape must of up to 4.2-4.5 pH with calcium carbonate contain small quantities of double calcium salt of tartaric and malic acid does not only encourage the precipitation of the tartrate alone, but an equimolecular mixture of calcium tartrate and malate (11). Successful use of a particular carbonate depends on the actual juice chemistry. For example, Zoecklein et al (13) demonstrate that high-acid / high-pH juices are best deacidified with calcium carbonate because of the relatively high tartrate ion concentration, whereas high-acid / high-pH juices are best treated with potassium-containing salts to take advantage of potassium bitartrate precipitation.

9. Kluba, R.M., and R.S. Beelman. Influence of amelioration of the major acid components of must and wines form four French-hybrid grape cultivars. Am. J. Enol. Vitic. 26:18-24 (1975).

Some common words found in the essay are:
MACERATION Carbonic, DEACIDIFICATION Acidity, OSMOSIS Various, DESSICATION GRAPES, AMELIORATION Amelioration, RESULTING WINE, According Chauvet, According Jackson, According Robinson, CRYOEXTRACTION Cryoextraction, reverse osmosis, resulting wine, red wine, tartaric acid, final wine, carbonic maceration, calcium carbonate, red wines, malic acid, 6 9, acid final wine, quality resulting wine, dried grape wines, concentration sugars 1, high-acid / high-ph,
Approximate Word count = 3384
Approximate Pages = 14 (250 words per page double spaced)