21 



small openiru; leading inward through a siphon-shaped tube bent back upon itself 

 an. I teniiinatini: at a point close fo the bottom. In making the determination, 50 to 

 60 cc of distilled water an- placed in the larger flask, the smaller flask fitted into the 

 wide neck by means i.f a section f rubber tubing, 10 cc of wine run in and the water 

 heated in boiling. The steam passing through the siphon-tube and through the 

 wine carries out the volatile acids. No appreciable change in the volume of the 

 wine takes place. When the water is reduced to about 5 cc, the flame is removed. 

 On cooling the apparatus the remaining wine liquor is drawn down into the larger 

 llask. The small flask is rinsed .tin with a little hot water and the two flasks discon- 

 nected. The liquor is cooled and the fixed acids are titrated. 



This method has been employed in the laboratory of the Minnesota Dairy and Food 

 Department in the analysis of a number of samples of wine and in the investigation of 

 .11 or more of the common varieties of fruit juices, and has proven satisfactory not 

 only from the standpoint of conventem in manipulation but on account of the fact 

 that results appear to !> relia- 

 ble and concordant. It has 

 hem noted, however, that in 

 I hi.- method as in others the 

 volatile acid.- an- n<>t roll- 



hut are allowed to dissipate 



into the air, and it lia-^ seem* -d 



desirable to . ..nden-e th- 



pore and titrate the volatile 



in the distillate. l',\ 



joining a condenser to the 



flank containing tho Rumple 



there i- pn.\ ided an apparatus 



\\lnTfb\ may be 



det.-rniined in on.- operation 



l)oth tin- \ohitile and fixed 



itiM- portion of 



wine. 



The-tatement ,,f tin-method 

 proposed for total, volatile, and 

 fixed acid- i- '_'i\.-n m page 



13, 



In the laboratory of the < ali- 

 fornia Wine. \ssociat ion tl 

 lowin- method ,,f titnition i- 

 empl. 



i wine are measured into a 500 cc beaker without the addition 



of water. The nine i- well -haken to remove carbon dioxid and titrated directly 

 with tilth normal sodium hydroxid. In the case of heavy-colored wines, no indicator 

 I; the coloring matter of the wine indicates the end point of the titration. In 

 the case ni white wine-, the same method of procedure is followed excepting that 

 a little neutral litmus is added. In titrating light-colored red wines, it may be advis- 

 able to add litmus, but the indicator is never used unless absolutely required. 



A comparison of the results obtained by the various methods of determining total, 

 fixed, and volatile acids is shown in the accompanying table. Total acids were deter- 

 mined by the California Wine Association method, by the method of Windisch and 

 by the proposed new method based on that given by Breteau. Removal of carbonic 

 acid was assured before any of the methods were attempted. Fixed acids were deter- 

 mined by the method of Windisch, by the method of Sellier, and by the proposed new 



Fio. 1. Apparatus for determining volatile and fixed acids in 

 wine. 



According to letter received from C. S. Ash, chemist, California Wine Association. 



