Fermenting cellar

Yeast rests in fermenting cellars in beer breweries typically have a composition of 90% beer and 10% solids, mainly yeast. The amount of this waste material is 2-3% of the annual output. It can be sold as cattle feed or discharged. In a system with 4 m 0.4 pm ceramic microfiltration membranes, beer recovery amoimts to 42-62% the concentrate contains 23% solid matter [51]. Fluxes in... 

Bottom fermentation involves a primary and a secondary step. In the primary fermentation step, the cooled wort with about 6.5-18% dry mass extracted from malt ( stemwort ) is pumped into fermenting tanks, located in fermentation cellars cooled to 5-6 °C. The tanks are made of plastic-lined concrete, enamelcoated steel, aluminum or V2A steel. The wort is inoculated ( pitched ) with yeast in the form of a thick yeast slurry of Saccharomyces Carls-bergensis (0.5-11/hl) and fermented at 8-14 °C until more than 90% of the fermentable extract has been converted. The primary fermentation is completed in 7-8 days, at which point the yeast breaks , i. e., flocculates and settles to the bottom. The beer is transferred to large clean... 

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. 

The process of fermentation gives off heat, and the tanks may need to be cooled with chilled water coils, with jackets, or by cooling the cellar in which the tanks are located. When fermentation is complete, many beers are now pasteurized, in the same manner as milk (see Section 17.1). The beer is then cooled to just above freezing, filtered and left to age . Before final bottling, kegging or canning it will undergo a fine filtration to improve the clarity. 

The optimum temperature of fermentation of wine depends on the type, red wines working best at about 29°C while the white wines require a cooler condition of around 16°C. Heat is given off by the chemical process of fermentation. They are then traditionally matured and stored in caves or cellars at about 10°C. Much of the manufacture... 

A small diameter pipe 32 m long runs from the fermentation room of a winery to the bottle filling cellar. Sometimes red wine is pumped through the pipe, sometimes white, and whenever the switch is made from one to the other a small amount of house blend rose is produced (8 bottles). Because of some construction in the winery the pipeline length will have to be increased to 50 m. For the same flow rate of wine, how many bottles of rose may we now expect to get each time we switch the flow ... 

In addition to their importance in the chemical reactions of alcoholic fermentation, some inorganic components have a significant effect on the stability of wines. Problems frequently are associated with excesses rather than deficiencies of certain inorganic constituents. Generally, excessive levels produce undesirable effects by altering the color, appearance, or taste of the wines (48). An excessive level of inorganic constituents in wines may arise from many sources such as the inherent content in musts, winery equipment, cellars, and vineyard materials. 

Cellar practices were shown to influence the extent of M-L fermentation in Eastern wines (60). The highest incidence occurred where must was fermented immediately after pressing. The lowest incidence was found where only a portion of the must was fermented immediately and the remainder was pasteurized, cooled, and held in cold storage until fermenter space became available. The effect of sulfur dioxide concentration on incidence of M-L fermentation was not evaluated in that survey. 

The rate at which the M-L fermentation proceeds is a function of the generation time. As pH and temperature decrease, the generation time increases, and the M-L fermentation proceeds more slowly. These observations agree with the conclusions of Bousbouras and Kunkee (65) in relation to the effect of pH on the rate of M-L fermentation. Even at the low pH values observed in some of the native white wines, Leuco-nostoc organisms were able to develop and complete the M-L fermentation. The cool cellar temperatures did not inhibit the M-L fermentation... 

FIGURE 3.9 Principal component analysis projection of the sensory attributes of the Vin Santo obtained after 6 and 18 months of aging. Gray lines indicate the separation of the trials in relation to the use/nonuse of Vin Santo madre and of the commercial Saccharomyces strain, in their respective fermentations. (Legend Al, fermentation with madre addition and no yeast strain inoculation, under vinsantaia conditions A2, as Al, but under cellar conditions Bl, fermentation with madre addition and yeast strain inoculation, under vinsantaia conditions B2, as Bl, but under cellar conditions Cl, fermentation with yeast strain inoculation but without madre addition, under vinsantaia conditions), (from Domizio et al., 2007)... 

In the fermentations under the cellar conditions, higher ethanol concentrations were reached compared with those under the vinsantaia temperature conditions. This could be due to the combined stress effects on the yeasts of alcohol and high temperatures during the summer period in the vinsantaia aging. In the Vin Santo obtained without inoculation with the commercial starter, satisfactory ethanol levels were however reached (13.7-15.3%, v/v). 

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