JULY 15, 1938
ANALYTICAL EDITION
FIGURE 4.
SHIPPING
353
FLOOR O F C.4RA3fEL DEPARTMENT
Pour into oil sample bottles, pasteurize, and seal. Set aside for 24 hours and record observations.
Tests Specific for Brewers' Caramel The requirements for a caramel in beer are entirely different from those for a carbonated beverage, pharmaceutical, or distillers' caramel. Brewers' caramels are sometimes burnt from malt sirup and designated malt caramels; more often they are burnt from mixtures of malt and corn-sugar sirup. Excellent bren.ers' caramels may be burnt entirely from corn sugar, with the proper burning formula, and add only color to the beer. Those from malt contribute flavor in addition. The pH of the caramel, particularly after dilution, is important (2, 3, 4,5 ) . The caramel must not fade or bleach when boiled n-ith hop? and it must be chill-proof-i. e., there must be no sedimentation or fading when the beer is chilled, either in brewery storage or previous to its consumption. HOPSTEST. Run 200.0 ml. of the stock caramel solution into a 500-ml. flask, add 1.0 gram of dried hops (pale green in color), cover the flask n-ith a small beaker, and boil gently for 15 minutes. Cool and filter through a Gooch crucible or Hirsch funnel, prepared with a layer of asbestos, over Fhich is a layer of FilterCel. Wash and make the filtrate to 1 liter. Compare with a control made from 50.0 ml. of the stock caramel solution diluted with distilled water to 250.0 ml. Record the percentage of the color remaining after boiling with hops, employing the respective Lovibond readings to determine the loss, i f any. CHILL-PROOF TEST Chill two bottles of beer, to n hich color is to be added, from 0" to 4' C (32' to 39" F.) bv means of an ice bath For control purposes, remove the cronn cap from one and immediately recap Remove the crolin cap from the other bottle, add 1 gram of color, and recap. Agitate the beer until the caiamel is dissolved. Place both bottles in an ice bath or iefrigerator for 2-1 hours and examine foi appearance of haze or vdiment. U.uall? 24 hours will suffice for this te-t.
Summary To illustrate the type of data obtained by this procedure, three typical analyses of commercial caramel colors sold for carbonated beverages are given in Table I.
Literature Cited ( 1 1 .issoc. Official Agr. C h e m . , Official a n d T e n t a t i v e M e t h o d s , 4 t h e d . , p. 516 (1935). (2'1 Briant, Lawrence, J. Inst. Breu'ing. 18, 673 (191%). (:{I Deghomont. A , , A n n . t u n i d . . [?I 1. :327-3!2 , 1934 .
(4) F a w c e t t , G. S.,J. SOC.Chem. Ind., 1996, 81. (5) Harman, H. W., and Oliver, J. H., J. Inst. Brewirig, 31, 577 (1925). (6) Salamon, A. G., and Goldie, E. L., J. SOC. Chern. Ind., 19,301 11900).
RECEIVED June 18, 1937. Presented before the Division of Sugar Chernlstry a t the 92nd Meeting of the American Chemical Society, Pittsburgh, Pa., September 7 t o 11, 1936.
Counting Drops with the Photoelectric
Relay GEORGE TV. JOSTES Pasadena Junior College, Pasadena, Calif.
T
HE photoelectric relay may be used to count drops of
transparent liquids. By suitable regulation of the cross qection of the light beam used, drops forming in the beam will reflect and refract sufficient light to act like opaque objects This will cause the photoelectric cell t o produce electrical impulses which may be used to count the number of drops for an interval of time or to regulate the rate of dropping. I n the apparatus used by the author, the beam of light iu modified by vertical slits 0.5 ern wide by 1 em. long. The beam run3 horizontally across the source of drop? and directly to the photoelectric cell, being interrupted as the drop forms and returning to normal after it has fallen. K i t h the potentiometer set a t 226" and an electiic relay counter operating on 18.6 volts direct current, it Tyas found possible to count drops up to 478 per minute. Faster counts are difficult because of the tendency of the drops to lose their identity and form a continuous stream. Drops may be enclosed by transparent mateiial, so that they are neither mechanically damaged nor chemically contaminated R E C E I V E> lDa r c h ?I>,1'3.38
