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.
Solutions of vanillin are probably the most convenient and practical preparations the carbonator can prepare. Estimating that the yield of vanillin from vanilla bean is but one and one-half per cent, as stated, then one pound of vanilla bean will contain 115.2 grains of vanillin; assumed that the yield will even be two and one-half per cent., then 192 grains of vanillin per pound could be obtained. In the mean the yield would be 153.6 grains per pound of vanilla bean. As the artificial vanillin, when properly prepared, is perfectly equal in aroma to natural vanillin, and as it is much cheaper than the corresponding quantity of vanilla bean or the natural or true vanillin, it is economical to employ the artificial product, which is freely soluble in alcohol. The crystals of vanillin dissolve but slowly in twenty-five per cent, alcohol, but almost instantly in strong alcohol, which solution may then be diluted without change.
Tincture of Vanillin. - Artificial vanillin, one ounce; alcohol of 95°, two pints. Dissolve the vanillin crystals in the alcohol, then dilute by adding six pints of water to make one United States gallon.
Tincture of Vanillin and Coumarin. - Artificial vanillin, six drachms; coumarin, two drachms; alcohol of 95°, two pints. Dissolve and dilute as before to make one gallon of tincture.
Compound Tincture of Vanilla Flavor. - To the artificial flavor prepared after Formula I. or II. add about two to four drachms of each soluble essence of cinnamon or cassia, which produces a nice combination of aromas.