This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
By a patent process, of German origin, the oils of lemon and orange, as well as others of the same nature. are concentrated to extraordinary degrees of strength. "The constituent containing the oxygen is the bearer of the aromatic principle of essential oils, and which gives it a value," is asserted. The oils of lemon and orange have hitherto been claimed to be free from oxygen, but it is now contended they both contain an oxygen compound, to which the aroma and taste are due.
Fig. 419. - Apparatus for Determining the Boiling Point of Oils.
This method of manufacture is said to effect a complete removal of the terpenes, compounds of carbon and hydrogen, from the essential oils. When it is considered that the atomic weight of hydrogen is one, and that of carbon twelve, while that of oxygen is sixteen, it becomes evident that the essential oils, freed from all hydrocarbon compounds, must be of a higher specific gravity than those which still contain some of these worthless constituents, and the value of an essential oil increases with its gravity.
Intense odor and taste is a characteristic of these oils, which are made by practical distillation, and fully justifies the term concentrated in connection therewith. As compared with other oils, their strength is. as follows, to quote a few familiar to bottlers, viz.: Anise, twice as strong; cassia, twice as strong; lemon, thirty times stronger; orange, thirty times stronger; cloves, twice as strong; coriander, six times stronger, etc. Unusual care and skill should be exercised in the use of these essential oils, as a drop one way or the other would make a vast difference in the. flavor of the drink being compounded; but beverage manufacturers, capable of handling them intelligently, would, doubtless,have no difficulty whatever, besides being protected against adulterations so rife in these days of unscrupulous mercantile competition and rivalry.