256 ANNUAL OF SCIENTIFIC DISCOVERY. 



volatile oil, developed during the roasting, existing in extremely minute 

 quantity, and to which coffee owes its delicious flavor. 



In this country a really good cup of coffee is the exception rather than the 

 rule, and this may probably be attributed to the nation from which we are in 

 a habit of selecting our cooks, since there is nothing in the whole culinary art 

 which requires more " sense" than the preparation of good coffee. The ex- 

 periments were instituted with a view of ascertaining whether a portable 

 coffee, so simple in its operation that it can not be spoiled, could not be pre- 

 pared for a price at least as low as that for which the raw or roasted material 

 may be offered. This was only to be hoped for by extracting from the berry 

 a larger amount of its nutritive substance than is done in the household, and 

 in such proportion as would pay the expense of the operations to which it 

 must be subjected. The attempt was not successful, yet some of the con- 

 clusions arrived at by the experiments are of interest 



In respect to the most important part of the operation of making good coffee 

 (the roasting), it is recommended that the roasting should take place in a 

 cy Under, constantly turned over a bright fire ; when a white smoke begins to 

 issue from the joints of the cylinder, its contents must be carefully watched, 

 and every few minutes a few grains extracted, and their color and brittleness 

 examined. As soon as they break easily into several fragments by a slight 

 blow, at which time the color will be a light chestnut brown, the operation is 

 completed, and the coffee, if in large quantity, must be cooled, by taking por- 

 tions up in a large tin cup, and letting them drop through the air. The quan- 

 tity of aroma which might be supposed would be lost in this way is incon- 

 siderable, and the danger of over-roasting, if the coffee is left in a heap, or 

 covered up, is great. The coffee, both roasted and ground, may be kept in 

 quantity without loss of flavor, if the vessel be corked air-tight. The best 

 form of coffee-pot was found to be that which has an upper compartment, 

 with a perforated bottom, upon which the coffee is placed, and the boiling 

 water strained through. But in preparing the infusion in any way, both the 

 coffee and the water should be measured in the proportion of a half an ounce 

 in weight of coffee to a cupful of six fluid ounces of water, for each cup of 

 the infusion. A small measure, containing somewhat less than an ounce of 

 water, will hold half an ounce weight of ground coffee. It is important to 

 keep the coffee-pot perfectly clean, as the least musty smell indicates a dis- 

 agreeable taste, which is imparted to the coffee. 



Experiments were made to ascertain whether the aroma lost in roasting 

 coffee might not be collected advantageously. The volatile products generated 

 in roasting were all carefully collected. Seven pounds of good Mocha coffee 

 gave a little more than two ounces of dark liquid matters, possessing no very 

 noticeable properties ; and in no instance could any product be obtained of 

 sufficient quantity or reaction to warrant any advantage in a practical point, of 

 collecting the aroma. It appears in reality that but a smaU quantity of aroma 

 is in reality lost by roasting, and what is dissipated is mingled with very dis- 

 agreeably-smelling vapors, from which it would be difficult to free it. An 

 experiment was also made to ascertain whether the fragrant volatile oils 

 might not be driven from roasted coffee by steam, and a dried extract of the 



