WINE 621 



proves but the passage of the wine is retarded. The first wine is passed a second time 

 through the filter and as soon as the rate of nitration becomes too slow, the operation 

 must be stopped and the filtering surface renewed. 



For wines containing little sediment, the filter must be primed. This is accom- 

 plished by putting some finings in the wine first passed through the filter. The 

 priming is more effective and the output of the filter much increased if a little in- 

 fusorial earth is used with the gelatin. 



For the more perfect clearing of old wines some form of pulp filter is used. These 

 are various devices by which the wine is forced through a mass of cellulose or as- 

 bestos pulp and freed from all floating matter. Some of the best of these, carefully 

 used, remove nearly all of the bacteria present. 



PROHIBITION AND WINE. Legislation restricting or prohibiting 

 the manufacture, sale or use of alcoholic beverages has profoundly 

 affected the industry, especially in the United States, where the 

 making of wine and other alcoholic beverages on a commercial scale 

 is now illegal except for sacramental and other specified purposes. 

 Whether it will be permitted as a home industry for family use is still 

 uncertain. 



Other uses for wine-grapes are therefore being sought. In the 

 eastern states many can be used for the manufacture of grape juice. In 

 California the most promising means of profitably disposing of the crop 

 are drying and the manufacture of grape syrup. These products, 

 especially the latter, will have some value as foods but their main outlet 

 must be, at first, in those countries where wine-making is permitted. 



Wine and vinegar can be made from both of these products by essen- 

 tially the same methods described for fresh grapes. The dilution of 

 the syrup and the extraction of a must of suitable concentration from 

 the dried grapes offer slight mechanical difficulties which can easily be 

 overcome. The use of starters of selected yeast will be necessary and 

 will offer some difficulty in operation on a small scale. 



The quality of the wine will be inferior in some cases and fair to 

 good in others. The color of red grapes is almost entirely destroyed by 

 sun-drying but remains in grapes dried in evaporators. The aromas 

 and flavors of the grapes are modified also more by sun drying and 

 concentration. The effects of these modifications in the resulting wine 

 are both favorable and unfavorable. The wines will have less marked 

 aromas but will age more quickly. The wines made from dried grapes 

 will tend to be high in tannin and extract; those made from grape syrup, 

 low in acid and extract. A combination of the two raw materials 

 will probably give the best results. 



