ACIDITY OF WINE. 4II 



a strength of 27.9° Ballino-. In nine half-litre bottles 400 c.c. 

 of this must was placecl. closed with perforated corks and con- 

 centrated sulphuric acid air-seals, and then sterilized for an hour 

 in a steam jacket. This was done in all subsequent experiments. 

 The bottles were inoculated on 27th October. 1916, with two- 

 days'-old cultures of the followinu' yeasts: GFT i, JJM i. JJM 

 -• JJ^i r>< JJ^[ ^^' t^JJ I- (jreen i. Green 2, Green 3. The tem- 

 perature in the thermostat was kept at about 25° C. On the 

 20th November the fermentation was over in every case, and 

 rafter the 24th November the loss in weig-ht of the bottles was, 

 very slight. The bottles were now analyzed. The results are 

 embodied in 



Table I. 



r.FT JJM JJM JJ^r TJ^^ PJJ (incn.i.rcon.Grccn. 



r I 2 



Loss in weiglii in 



gr ... 30 40 ,51 J2 27 2!< .3^ 33 31 



Alcohol in wine, as 



volume per cent. 9.15 -8. So ').,'>i2 9.74 8.40 8.48 9.78 9.32 to. 18 

 Volatile acid, as 



gr. acetic acid 



per litre 2.15 2.26 1.68 1.68 2.21 2.24 1.87 1.94 i-f/' 



These fermentations were incomplete, so that the wine was 

 still sweet. The \-olatile acid was very high, there being- con- 

 siderable dilterences between the different yeasts. The initial 

 volatile acidity was very low, l)eing about 0.1 per mille. 



B. Expei^intcnts zvith Must of 25.0° Balling. — Sterilized 

 must was slightly evaf^orated to a concentration of 25° Balling. 

 The ex])eriment was otherwise as before. The temperature of 

 the thermostat ran from 22-2<S° C, being most of the time near 

 25° C. The bottles were inoculated on 20th January, 1917. 

 with the same yeasts as alxjve, and in addition HeA.,, HaB.., PBg. 

 The experimental must used contained 0.14 ))er mille volatile 

 acid at the beginning of the exjjeriment. ' The ifermentations 

 were over by the 15th February, but, owing to there being njo» 

 gas, the analyses could not be made until two weeks later.. 

 Meanwhile the 1x)ttles were kej)t corked. The following results 

 were obtained : 



Tabic II. 



GFT I JJM I JJM 2 JJM 5 JJ^r 6 PJJ i 



Loss in weight in gr 39 42 44 45 3^ .>') 



Alcohol, in wine, as volume 



per cent _. . 14.01 14.20 15. lO 12.69 i5-07 T2.97 



Volatile acid, as gr. acetic acid, 



per litre 1.54 i..=^o 1.24 1.27 1.72 f.68 



Green. Green. Green. HeA3 HaB3 PB 2 



I 2 3 



Loss in weight, in gr 4r :i6 41 43 ,]6 Ti6 



.Alcohol, in wine, as volume 



percent. ... ... 13.72 J2.69 13.53 13.91 12.32 12.05 



V'olatile acid, as gr. acetic acid, 



per litre 1.52 1.58 1.52 1.64 0.94 1.22 



