142 COFFEE 



Test : — Factitious beans are heavier than water and sink ; where- 

 as, genuine coffee-beans are lighter and float. 

 2. Alcoholic treatment: 



(a) For sugar glazing: 



Procedure: — Higler's process is satisfactory and is as follows: — 

 Digest lO grms. coffee-sample three times for V2 hr. with quanti- 

 ties of 100 c.c. cold alcohol (i' vol. 90% alcohol to i vol. HgO). 

 Decant alcohol each time and make up to 500 c.c. Filter. 

 Evaporate a considerable portion to dryness. Weigh and deduct 

 ash. (To allow for action of solvent on beans, deduct 0.83 for 

 each 100 parts of dry coffee. Difference may be taken as due to 

 caramel.) 



(b) For shellac and resin: 



Procedure: — Shake beans with alcohol for 10 minutes. Evap- 

 orate to dryness in dish. Ignite residue. 



Test: — Characteristic resinous odor indicates adulterant. 



(c) For graphite (which adheres closely and is not removed by 

 shaking) : 



Procedure: — Warm samples with alcohol containing potassium 

 hydroxide. 



Test: — Graphite readily removed if present. 



3. Spath's petroleum treatment for facing-matters such as fat, 

 vaseline, paraffin, wax, etc. : 



Procedure: — Extract 100-200 grms. sample with light petroleum 

 for 10 minutes. Decant petroleum spirit; repeat process several 

 times. Evaporate petroleum extract to dryness. Digest with warm 

 water. Extract fatty matter with light petroleum. Filter and 

 evaporate to dryness. 



Test: — Examine residual fatty matter by usual methods for 

 waxes and fats. 



II. Roasted and Ground Coffee. 



A. Physical Tests: 



I. Dry treatment: 



Procedure: — Press sample between fingers. 

 Test: — If it cakes, adulterated — probably with chicory and 

 cereals. 



