Wine Musts

These components and their changes are very largely interrelated. 

When the sugar content is high enough the activity of the first fermentation prevents much action by harmful organisms. Later, enough alcohol has been produced to prevent the growth of these. A proper sugar content lies between 18 and 28%. 

Organic acids, especially tartaric, serve to produce sound and healthy wine in a number of ways. Sufficient acidity encourages sound fermentation and inhibits the growth of the disease bacteria. Sufficient acid ensures a full tasting wine which will store well, while insufficient acid means a flat taste and short life. Acid also ensures a better extraction of color from the skins. 

Tannin, which is derived by extraction from the skins, seeds and stems of the grape is an essential constituent of the wine. It serves to confer disease resistance on the wine, aids remarkably in the clarification and produces a more brilliant color. On the other hand, an excess of tannin confers an astringence on the wine which delays its final maturity, although in the end the wine is more mellow for it. 

Red Wines.—The production of wine falls naturally into two broad divisions, red and white wines respectively. The production of champagne and of other fortified wines may follow in 

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Various methods have been developed to eliminate biases which otherwise can skew results. The wines must be presented without identification, although the taster should be told the type of wines (the best strawberry wine should rate very poorly in a Cabernet class). Eor the most informative results, many details of coding, presentation order, repHcation, etc must be considered. The results must be statistically examined to estimate whether or not they could have been obtained accidentally. Statistical analysis is an entire field in and of itself, and wine studies have contributed greatly to its present sophistication, as appHed in the flavor field. 

Varietal labeling is an important quaUty factor in the United States, and indirectly elsewhere because only certain specific varieties are planted in each prestigious foreign area. U.S. law currently requires that 75% of the wine must come from the V. vinifera variety named on the label. Concord-type varieties only require 51%, owing to their intense, distinctive flavor. If more than one variety is named, the relative amounts must total 100%. 

Careful records must be kept to enable verification of compHance. Each lot of wine must be traceable back to the grapes and vineyard. Tanks must be carefully gauged and the capacities recorded on them. If the wine is to be labeled "estate botded," not only must the wine be fermented, processed, and bottled by the state winery at thein Hsted address, but the vineyard must also be owned or controlled by that winery. Other label terrninology, subject to some further intricacies, are "produced," ie, fermented 75% or made into a different class of wine "prepared," "vinted," or "cellared," ie, subjected to ceUar processing or aging without changing the class of wine "blended," ie, combined at the stated address, wines (probably purchased) of the same class and type and "botded" or "packed" by the stated winery. 

And the reason why the wine must stand (rather than the reaction occurring immediately the oxygen enters the bottle on opening) is that the reaction to form the ester is not a straightforward one-step reaction the first step (Equation (8.39)) is quite slow and occurs in low yield ... 

Dextrose was doubtless known to the ancients because of its occurrence in granulated honey and evaporated wine musts. Efforts to prepare the sugar as an article of commerce were not made until the beginning of the nineteenth century. 

It udll thus be perceived that the nature of the soil for the dry and finest wines must be calcareous, even to pure chalk in all events it must be sufficiently so to influence the vine most essentially during its growth and that for sweetand luscious wines, the nature of the soil is of far less moment, such wines being grown... 

Continuous Monitoring. Prompt completion of any operation once it has begun in the cellar is important. Minimize the number of physical operations that any wine must submit to. When it can be seen very early that a given filtration is not providing the desired product clarity, report it at once. By changing the defective set-up promptly, you are eliminating the need to filter the wine twice. 

P Martin, C Polo, MD Cabezudo, MV Dabrio. Dansyl amino acids behavior on a Radial-Pak C18 column. Derivatization of grape wine musts, wines, and wine vinegars. J Liq Chromatogr 7 539-558, 1984. 

Special reference must be made to the study of fermentations, which besides the wines, musts, and beers already mentioned, is of great interest in other alimentary sectors as well. A large number of products undergo fermentations before being put on the market (for example, byproducts of milk, vegetables, olives, cocoa, etc.). 

The recovery of flavors and fragrances from diluted aqueous streams may be of industrial interest under different circumstances (1) recovery of complex aroma profiles and/or target aroma compounds from active biocatalytic processes (2) recovery of complex aroma profiles and/or target aroma compounds from natural extracts and industrial processes aqueous streams. Pervaporation offers a unique solution for the recovery of complex aroma profiles. An example for the recovery of complex aroma profiles, faithful to their origin, is the recovery of a muscatel aroma from an ongoing wine-must fermentation [31, 32]. 

According to the present EU rules of wine classification, only wines complying with the specific DOC/DOP rules (see Table 3.4, above) can be labeled as "Vin Santo," while those wines that are produced by alcohol addition to partially fermented wines or to base-wine must be labeled as Vin Santo "vino liquoroso" or "v. I." (fortified wine). 

Nevertheless, honey and wine musts have different compositions in regard with sugar content (nearly 3 times higher in the former) and nitrogen concentrations (about 100 times higher in the last). Thus, wine... 

A natural wine must be used in the making vermouth or the flavored special natural wines. Such a wine may also be made with the usual permitted cellar practices. 

Fermentation generates heat, and red wines must have some type of temperature control during their fermentation. They must not be allowed to get too hot or to become too cold. Ough and Amerine (18) recommended temperatures of 18°-29° C and found that cap temperatures can exceed liquid temperatures by over 6° C. In large stainless steel fermentors, the author has noted cap-liquid temperature differences of 11°. 

Before the wine is bottled, it must be rendered stable to qualitydegrading changes in the bottle. Malic acid stability has been discussed already. Other changes that the wine must be stabilized against are precipiation of cream of tartar, unstable color deposits, iron and copper casse, oxidation, and, of course, microbiological breakdown. 

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