Calculate from the following formulas: 



A. 6=2 A-j-E, when O=original extract of wort, A=alcohol by weight, and E= 

 extract of dealcoholized beer. 



B. O=(AXl-92)db E. Same as formula A, except that factor for converting alcohol 



to sugar is theoretically more accurate. 

 p _ * 



C. O=E+^ 7 ; z-when E=real extract and A = apparent extract. 



1. ZoZ 1 



when A=alcoho1 and E=extrMt 



E. G=sp-f-st, where G is the specific gravity of the original wort, sp the specifi- 

 gravity of the dealcoholized beer, and si the amount of alcohol destroyed by fermen- 

 tation, as obtained from table in Allen's Commercial Organic Analysis, volume 1, 

 page 135. 



From extract calculated as in A, B, C, and D, compute from Schultz and Oster- 

 mann's, Ellion's, and Balling's tables the specific gravity of the wort. 



DEGREE OF FERMENTATION. 



200 A 

 Calculate from theformulaD= g in which D is the degree of fermentation, A the 



percentage of alcohol by weight, and B the original extract. 



TOTAL ACIDS. 



A. Heat 20 cc of the sample to incipient boiling to liberate carbon dioxid and titrate 

 with decinormal sodium hydroxid, using neutral litmus paper as indicator. Each 

 cubic centimeter of decinormal alkali employed is equivalent to 0.009 gram of lactic 

 acid. The number of cubic centimeters of olecinormal alkali employed in titrating 

 20 cc of the beer is multiplied by 0.045 for the acidity expressed as grams of lactic 

 acid per 100 cc. 



B. Calculate as cubic centimeters of decinormal sodium hydroxid required to neu- 

 tralize the acidity of 100 cc of the sample. 



VOLATILE ACIDS. 



A. The volatile acid as acetic acid is determined by titrating 20 cc of the alcohol 

 distillate with decinormal sodium hydroxid solution, using phenolphthalein as an 

 indicator. The number of cubic centimeters of decinormal alkali employed multi- 

 plied by 0.030 gives the acidity expressed as grams of acetic acid per 100 cc. 



B. Calculate as cubic centimeters of decinormal sodium hydroxid required to 

 neutralize the acidity of 100 cc of the sample. 



REDUCING SUGARS. 



Twenty-five cubic centimeters of the beer free from carbon dioxid are diluted with 

 water to 100 cc. The reducing sugar is determined in 25 cc of this solution, as 

 directed on page 49, Bulletin 65, the solution being boiled 4 minutes instead of 2 

 minutes. Express the results in terms of maltose equivalent to the copper reduced, 

 according to Table IX, page 144, Bulletin 65. 



DEXTRIN. 



A. Employ Sachsse's method for the hydrolization of starch and determine dex- 

 trose according to Allihn, as follows: 



Fifty cubic centimeters of beer and 15 cc of hydrochloric acid, specific gravity 

 1.125, are diluted to 200 cc, attached to a reflux condenser and kept in a boiling 

 water bath for 2 hours. Neutralize with caustic soda and dilute to 250 cc (or 300 cc 

 in a beer with high extract). Add 25 cc of the solution to the boiling Fehling 

 solution and boil 2 minutes. Multiply the oxid of copper found by 0.8 to obtain 

 the corresponding amount of copper and refer to Allihn' s dextrose table (Table 

 VIII, p. 143, Bull. 65). The amount of dextrose thus found multiplied by 20 (or 

 24 if diluted to 300 cc) and divided by the specific gravity equals the dextrose in 

 the original beer. From this figure subtract 95 per cent of the amount of maltose 

 in the original beer and multiply the remainder by 0.9, the result being the per- 

 centage of dextrin in the original beer. 



[Cir. 33] 



