Tincture of Vanilla.
By R. ROTHER.
After vanilla pods there are few if any other crude articles to be found in mercantile pharmacy having such a diversity of quality as inferred from their market value. In consequence, tincture of vanilla for flavoring purposes can be prepared rich in vanilla at a relatively moderate cost, and scant in vanilla at a comparatively exorbitant cost. Connoisseurs claim that they can easily discern the differences in these various preparations. Since, however, the consuming public are in no sense experts in such matters, all grades of these products find a ready market. Viewed from the standpoint of the trained palate, the public taste is exceedingly perverted when it deliberately prefers tonka-mixed vanilla or even tonka pure and simple to the best vanilla.
Manufacturers of flavors have not been slow to recognize the advantage of such a disposition to themselves, and as a consequence of the greatly increased demand the cost of tonka bean has steadily risen to an unprecedented level of late years. The cost of vanilla has, however, appreciably declined. That this was caused by the introduction of artificial vanillin and the decreased demand for pure vanilla flavor is, however, not the case. The probable reason is very likely to be found in the new natural sources of supply that have of recent years been developed. The fresh supplies appear to be so abundant and rich that the natural vanillin obtained therefrom has not only crowded out the synthetic article, but incidentally reduced the cost to a remarkable degree.
The Pharmacopoeia has at this late day embodied a formula for tincture of vanilla. It bears a rather antique form, and it is perfectly safe to add that pharmacists who have occasion to prepare large quantities of the tincture will ignore the official process in every particular. In this preparation there is no need for the presence of any sugar whatever. Such an unusually strong alcoholic menstruum as is officially used is also unnecessary, to say nothing of the objectionable features still outstanding.
Macerating the sliced pods with diluted alcohol constitutes the simplest and best process that can be applied. Where much material is operated on, the extraction is preferably accomplished by the procedure of remaceration. When tonka is conjointly used the operation need not be varied, as its relation to the menstruum is even more favorable than that of vanilla. The crude material may be exhausted with diluted alcohol, separately or coincidently. Their combined extraction is, as a rule, more convenient.
A tincture containing one ounce of each vanilla and tonka in the pint is very satisfactory, although half an ounce of tonka may ordinarily suffice.
Estimating that the yield of vanillin from vanilla pod is 2 per cent., and that of coumarin from tonka bean the same, then eight troy ounces of each will contain, in round numbers, 80 grains of the principles respectively; it is, however, allowable that it is much less even from apparently the best material. This amount of pure principles costs scarcely half that of an equivalent quantity of good crude substance. However, the writer has for some time past prepared a tincture from pure crystallized vanillin and coumarin, containing three drachms of the first and one drachm of the second, or half a troy ounce of the two together, in the gallon. This is twice the best possible yield of the crude material, or twice the ordinary strength of the-tincture. As the composition here is largely in favor of vanilla, the cost of the resulting product is correspondingly enhanced. It is, however, barely more than half that of a proportionate amount of the raw product. This tincture is therefore twice as strong at half the cost of that as ordinarily made, or a difference in its favor as four to one.
Although diluted alcohol is necessary for extracting the activity from the crude substances, a much weaker alcohol will suffice for simply holding the principles in solution. Two pints of alcohol to the gallon of tincture is ample. The crystals dissolve but slowly in 25 per cent. alcohol, but almost instantly in strong alcohol, which solution may then be diluted without change. It has been deemed advisable to add some glycerin to the tincture, as it is held that such addition is beneficial in bringing out flavors of all kinds. The tincture is colored with liquid caramel or sugar color, and thus presents the full appearance of that obtained from the natural bodies. It is prepared according to the following formula:
|Vanillin, crystallized||3 drachms.|
|Coumarin, crystallized||1 drachms|
|Caramel, liquid||2 fluidrachms.|
|Water, sufficient to make||1 gallon.|
Dissolve the vanillin and coumarin in the alcohol and add four pints of water. Mix the caramel and glycerin with one pint of water and pour it into the first solution, together with enough more water to make the tincture measure one gallon, and filter it if necessary.
The American Journal of Pharmacy, Vol. 57, 1885, was edited by John M. Maisch.