Stopped fermentation

In an experiment, Gomes (2010) produced distinctive meads by varying when fermentation was stopped and whether brandy was added. Of these, the most appreciated by a Portuguese consumer panel was the sweetest, independent of the alcohol content. The sweetest mead was obtained after prematurely stopping fermentation early by the addition of brandy (77% alcohol). The product had an alcohol content of 18% (v / v) and a sweetness equivalent to 8° Baume. The alcohol content was then adjusted to 18%, 20%, and 22% (v/v). 

The classification of port wines according to sugar content is presented in Table 5.5. The sweetness level depends on when grape spirits were added to stop fermentation. The probable alcoholic degree of the juice... 

Cessation of fermentation is one of the technical problems in botrytized wine production that needs further research and development. Dimethyldicarbonate (DMDC) is now considered a reliable inhibitor which could replace some of the S02. Although DMDC has proven suited for treating wines especially just before bottling, its use in Sautemes production has been investigated (Divol et al., 2005). The results showed that DMDC at a rate of 100-200 mg/1 stopped fermentation but did not replace the antioxidant functions of SO2. Sulfite addition was necessary to limit wine oxidation and yeast reactivation. 

A number of different species dominate the fermentation at different times Saccharomyces is dominant only towards the end. K apiculata with cell dimensions of (2-4.5) iJ.m x (5-8) /.im, usually dominates the early stages, along Metschnikovapu/cherrima and Torulopsis stellata. It stops fermenting and... 

In addition to the many different types of tvine, there are specialty wines such as dessert wines which show a relatively high extract content this is achieved through the addition of concentrated grape juice or by means of alcohol addition to stop fermentation and preserve the residual sugar. Another kind of specialty wines are sparkling wines that are produced on the basis of different techniques (e.g. en tirage) which lead to the characteristic high level of carbonation in the finished product. 

The following is an outline of his experiments The sugars were fermented with 5 per cent, of sodium carbonate, which must not be added to the liquid aU at once. A less quantity of the alkali diminishes the yield of glycerine, whilst a larger quantity stops fermentation other alkaline substances may be used, but sodium carbonate is preferable on accotmt of its cheapness. It should be added as soon as the fermentation has well started, and in as large quantities and as frequently as is possible without stopping fermentation. The earlier the addition of the alkali, the higher the... 

Broth Is usually heated to stop fermentation, neutralized, and subjected to shear to release polymer attached to cell walls. Figure 2 summarizes effects of various orders of carrying out these treatments on viscosity. It is clear that the first blending to which the sample is subjected has the greatest effect on the viscosity. 

Anthocyanin-pyruvic acid adducts are known to be more abundant in Port wines than in red table wines, as seen from previous analysis in our laboratories (data not shown) and as referred by other authors (77). This feature may be related to the higher levels of pyruvic acid expected in fortified wines as a result of a shortened fermentation. In fact, when wine spirit is added in order to stop fermentation, the pyruvic acid concentration is expected to be higher than when the fermentation is allowed to go to dryness. Effectively, the pyruvic acid excreted by the yeast at the beginning of the fermentation is further used in the yeast metabolism (35). Therefore, could favor the formation of anthocyanin-pyruvic acid adducts. 

The source of sugar varies. Grape juice is used to make wine, using natural yeasts on grape skins. Allowing fermentation to stop naturally produces a dry wine, with low sugar content. Stopping fermentation... 

Eortified wines such as port and sherry have high alcohol content and are typically sweet. During fermentation, winemakers add distilled brandy to the wine. The alcohol kills the yeast in the wine and stops fermentation, thereby preserving more of the sugar in the grapes and simultaneously adding to the alcohol content. 

Causes of sluggish (slow) and stuck (stopped) fermentations include nutritional deficiency, inhibitory substances, processing difficulties, as well as bacterial antagonism (Section 6.6.2). Although various factors can contribute to a sluggish or stuck fermentation, the exact cause (s) of a particular occurrence cannot always be identified. 

Sorbic acid is not a winemaking tool. It does not affect the rules of mutage for sweet wiues. It is incapable of stopping fermentations that are underway. Sorbic acid is exclusively used for the conservation of sweet wines to avoid their refermentation. It can be added to wine after the elimination of yeasts by racking, centrifugation or filtration. 

In the past, some wines became sparkling spontaneously, when they were bottled with some residual sugar before fermentation was completed. They were unreliable to make, as the second fermentation was uncontrolled and could produce insufficient pressure, or, on the contrary, result in excess pressure that caused the bottle to explode. Several variations on this technique are still used today, but are now much better controlled. Fermentation is stopped by refrigerating the wine once it has reached a specific residual sugar level. Once it has been bottled, it is allowed to warm up naturally and fermentation is completed. This technique is relatively simple to use as the chilled must after stopped fermentation may be stored as long as required, then bottled at an appropriate time. 

It is recommended to stop fermentation (mutage) before fortification by refrigerating the must or eliminating the yeasts by centrifugation or filtration. 

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