BEVERAGES 131 



Ash. o-i to 0-3 per cent. About one-sixth is P 2 5 . 



Acidity. (i) Fixed as tartaric. Dilute 20 c.c, boil down, 

 repeat, add water, and titrate with N/10 NaOH, using 

 phenolphthalein as indicator (0-5 per cent and under) ; 

 (2) Volatile acid : 20 c.c. of the wine are well diluted, and 

 then titrated with N/10 soda, using phenolphthalein as 

 before. Deduct number of c.c. required for fixed acid 

 from number now obtained, and multiply difference by 

 0-006 == volatile acid as acetic. The fixed acidity is 

 calculated as tartaric : 1 c.c. N/10 NaOH = 0-0075 grm. 

 tartaric acid. 



Sugar. Take 50 to 100 c.c, boil off the alcohol, remove 

 colouring matter and other bodies with slight excess of 

 basic lead acetate, filter, remove lead, and treat with 

 Fehling's solution after dilution to 200 c.c. Varies from 

 o to 5 per cent ; in champagne, 4 to 10 per cent. 



Preservatives. Salicylic acid, formaldehyde, sulphites. 

 Boric acid is said to be naturally present in some wines. 



Colouring Matter. Soak gelatin (10 per cent) cubes in 

 sample for twenty-four hours, then cut them diagonally. 

 Natural wine colour penetrates less than one-eighth of an 

 inch, but artificial colours through and through. Or, the 

 Paris Municipal Laboratory test : Take a piece of recently 

 calcined lime and wet it with a few drops of the wine. 

 Natural red wine gives a yellowish-brown coloration ; wine 

 coloured with fuchsin or Brazil wood gives a rose colour, 

 and wine coloured with logwood gives a reddish violet. Or, 

 baryta water is added until solution is green, and then acetic 

 ether, and shake. Allow to stand until acetic ether separ- 

 ates, when if coloured, basic dyes present, if not, probably 

 only natural colour. Or, add diluted KOH until alkaline, 

 then mercuric acetate, filter; filtrate is red or yellow if 

 acid aniline dyes present, colourless if pure wine colour. 



Adulteration. Addition of tannin, alum, catechu; 

 plastering (addition of gypsum) ; blending ; pasteuriza- 

 tion ; saccharin. 



Piquette. An artificial substitute for wine, manufac- 

 tured in France (50 million gallons were made and con- 

 sumed in 1898). One pound of raisins and one pound of 

 dried apples are added to one gallon of water ; expose 

 mixture in an open vessel to the air for three days ; then 



