UTILIZATIOiSI- OF GRAPE POMACE AND STEMS. 



oil, the meal and tannin extract being of secondary importance in 

 point of actual value. The diafrram (fig. 3) illustrates the reduction 

 of this waste material 

 to the various com- 

 mercial products men- 

 tioned, 



Destemm/nq 



CREAM OF TARTAR 

 FROM GRAPE 

 STEMS. 



Heac/n^ 



Pressina 



Separt3c/'ng 



V 



The method of ex- 

 tracting the cream of 

 tartar from the stems 

 consisted in boiling 

 the ground stems with 

 an excess of water, 

 running off the water 

 extract, and concen- 

 trating it at atmos- 

 pheric pressure or by 

 means of a vacuum 

 pan to the consistency 

 of a thin sirup. "\Mien 

 allowed to stand, this 

 extract deposited crys- 

 tals of cream of tar- 

 tar, which were 

 thrown on a force 

 fdter or into a centri- 

 fuge and washed with 

 cold water, in whicli 

 the crystals are only 

 slightly soluble. In 

 this manner about 2 

 per cent of crude 

 cream of tartar Avas 

 obtained. The washed 

 crystals were readily 

 purified by recrystallizalion from a hot-water solution. 



The total quantity of wet stems (600 tons) would yield, therefore, 

 about 13.2 tons of crude cream of tartar, which, at 40 cents a pound 

 (a conservative figure for the crude crystals), would brinir a irross 

 revenue of $10,560.^ 



/ \ 

 Man Ufa. c curing 



Fiu. 3.— lii:igraiii showing the proiiucts oluainabli 

 grape waste. 



from 



"All estimates and prices quoted hereinafter, unless otherwise sijeclfled, are based on 

 prices obtaining in the win'er of 101!>-L'O. 



