[16] This article on flavoring extracts is furnished by the Joseph Burnett Extract Co., Boston, Mass.
Because of the distinct taste which the flavoring extract imparts to the ice-cream, it is important that it be of good quality. The vanilla extract is most common, but lemon, orange, pistachio, almond, various fruit, and others are used to some extent.
Flavoring extracts are prepared commonly by grinding or chopping the sources of their various flavors and steeping or dissolving them in alcohol; or by distilling them, wholly or fractionally; or, when necessary for any reason, simulating them by chemistry, or by the use of a flavor source to all intents the same as the original.
Extract of vanilla, properly made, is the pure essence of the vanilla bean, dissolved in alcohol.
Although there are fifty or more kinds of vanilla plant, the only one with a fruit suitable for use in flavoring extract is Vanilla planifolia, so called by botanists for its flat leaves. It is a native of the valley of Mazantla, in Vera Cruz, Mexico, seemingly the only place where conditions of soil and climate suffice to bring it to its highest point of cultivation. The other vanillas, native to various parts of Spanish America, are fit only for use in perfumery and soap, because, though aromatic, they are rank in taste.
—The plant of vanilla is an orchid, having roots in the air as well as in the ground. It clings to trees or frames, twining around them as it grows, and favors most a light, loose soil, well drained, with “quilted sunshine and leaf-shade,” a condition naturally brought about by the foliage of the protecting trees. In Mexico it is grown from cuttings set out in the forest, one to a tree; this support, together with 70 to 90 degrees of continued heat, frequent rains, and a final dry season being needful to its best growth. Frost is deadly, and in too close planting disease is likely to ravage the crop.
After eighteen months, the vine is clipped to check its growing until it bursts into flower, which occurs in September. The stem of the vanilla is thick and round, the leaves large, smooth and pointed, the flower beautiful, much resembling the tuberose, and delightfully fragrant.
Formerly the blossoms were fertilized by a small bee, which carried the pollen from one to another, for the plant is of two sexes. At present this is done by hand—a better way, inasmuch as only the best flowers need be fertilized, the plant thereby keeping vigorous and healthy. Artificial pollenizing developed from transplanting vanilla in the island of Reunion, where the crops originally failed for lack of insects to carry the pollen.
Following each blossom comes a small pod, but most of these pods fall off. The remaining ones mature in about six weeks, growing in bunches of six to ten, and resembling bananas, being five to ten inches long, yellow green, and banana-like in shape. They are watery and tasteless, without the pleasant aroma of vanilla, the well-known taste and smell of which must be brought out by curing. If left on the vine, they ripen slowly, but usually they are picked before they ripen, as otherwise they split in curing. When this happens they are known to the trade as “splits,” and are considered undesirable on account of their full and heavy flavor.
—After picking, the Mazantla beans are transported to Papantla, the largest town in the valley, to be cured. The process is laborious, and although somewhat primitive, very simple.
The beans are exposed on frames to the sun by day and by night are wrapped in blankets under cover. This continues, in fair weather, for about a month; then the beans are dried indoors for forty days more, until they turn a deep rich brown in color, and become delightful to the smell. If the weather is wet, they are moistened, blanketed, and heated in ovens, the heat being moderate and varied with the size of the beans; after which they are by turns exposed to the air and heat until cured. The sun drying is preferred, as it gives the beans better keeping qualities. Such is the process in effect, but in fact each bean is treated separately; for proper curing, to bring out the desired fine qualities of taste and smell, is of the utmost moment; and only native judgment, or the skill born of long handling, ever gives the real adroitness. Badly cured beans lack any stable taste or smell, and are likely to become moldy. Their use in trade is made possible, in this case, by scraping and chopping them up with poor and broken beans and those that fell early from the vines; then they are sold under the name of “Mexican cuts,” chiefly to manufacturers of cheap extracts.
—The long fine beans, resembling thin cigars, are molded, pulled, and tied in bundles of 100 to 150, varying in length from six to eleven inches, and in weight from twelve to twenty-four ounces. The bundles are packed forty to a tin, and shipped four tins to a case in sweet-smelling cedar boxes. The entire Mexican output is consigned to the United States, where it brings from seven to ten dollars a pound.
The Aztecs knew the properties of vanilla, and are said to have called the plant thilxochitl. They used the bean in making chocolate, through which it became familiar to their Spanish conquerors, and thus to Europe. The name vanilla is derived from the Spanish word vaina, meaning sheath or pod, and the suffix -illa, little. The use of vanilla in chocolate was its only notable one for many years, although during that time great medical properties were claimed for it. It was not until the eighteenth century that some person now unknown discovered its general utility for flavoring.
—Vanilla cultivation in Mexico was in the hands of the Indians for centuries, but in 1896 the government, claiming they had no title, drove them off and sold the land to Greeks, who now control the industry there.
Almost every European power has tried to grow vanilla in the tropics, outside of Mexico. Many of the early trials were failures; none has been a complete success, at least in so far as rivaling the fine quality of the Mexican product is concerned. Cuttings were transplanted in the island of Reunion and grown by artificial pollenizing, as has been said, but the resulting beans were not as good as the parent beans of Mexico. Reunion was formerly known as Bourbon Monarchy, but the French, who had every reason to hate the name, rechristened the island; the beans, notwithstanding, are still called Bourbon beans.
Vanilla grows in Reunion much as it does in Mexico, except that it takes longer to develop. The great difference is in the curing, for there, owing to the climate, the sun treatment is inexpedient. The beans, placed in baskets, are plunged into hot water for about twenty seconds, drawn out to drain for as many minutes, and then wrapped in blankets to be sunned during the warm hours for five to eight days. They are housed at night as in Mexico, but drying is also hastened chemically with chloride of calcium (the basis of lime). After curing, the beans are straightened, graded by size, smell, and soundness, bundled and packed in tins which weigh, when ready for export, from ten to twenty pounds each.
Tahiti exports a particularly inferior quality of beans. They are grown from Mexican or Bourbon slips, but the change of soil and climate imbues them with an unmistakable rankness, to which, up to within a few years, were added careless growing and packing, in nowise improving them. Although inspection by the French colonial government has somewhat bettered the care of these beans, their flavor is probably unchangeable. Tahiti beans are all shipped to the United States, whence those not used are reshipped to Europe. They are sorted here into three grades: pink label, best; white, fair; green, poor; but the only real difference is their length and appearance.
A small crop of beans grown from Mexican slips is raised in the island of Guadeloupe; they are known to the trade as “South Americans,” and are of low quality, without the finer characteristics of good vanilla.
The average world’s production of vanilla is as follows:
| Mexican: | ||
| Whole beans | 240,000 | pounds |
| Cuts | 80,000 | „ |
| Bourbon: | ||
| (From all sources) | 700,000 | „ |
| Tahiti | 450,000 | „ |
| South American | 25,000 | „ |
| Total | 1,495,000 | „ |
—Vanilla beans, glycerine, sugar and alcohol are the only ingredients requisite or advisable in a vanilla extract; consequently the excellence of such an extract rests in the quality of the beans and of the alcohol employed, and in the means and skill devoted to employing them.
The process at its best is chopping or grinding the beans and treating them with dilute alcohol of 20 to 70 per cent strength, in the proportion of one part of the bean to ten parts of the liquid, the alcohol acting as a solvent. The old-fashioned and as yet unequaled way is to treat the beans by steeping and dissolve out the soluble matter. The chopped beans are placed in a cask and the dilute alcohol poured over them; they are then left to soak for one to twelve weeks, when the extract is drawn off and the sugar added to it, and it is either bottled immediately or aged. Aging greatly improves it, but few manufacturers care to assume the added cost.
Another method of obtaining the extract is by distillation; that is, by evaporating and condensing the liquid in which the beans have been steeped. There is also a machine which effects the result more rapidly by pumping the liquid steadily through the chopped beans, at an even temperature. Many other means are also employed. They are all cheaper than the old-fashioned way, but have nothing to recommend them from the consumer’s point of view. Distillation, for example, might ruin the delicate flavor of choice Mexican beans; while no process would ever impart one to Bourbons or Tahitis.
—Given the highest grade of Mexican beans and pure cologne spirit—the trade name for doubly distilled alcohol—with the old-fashioned method of compounding them, and there remains to vanilla extract-making only the knowledge and skill available in the process. These, however, are far from comprising the whole secret of success. Although seemingly a matter of chemistry, extract-making has always been a stumbling-block to the chemist. Chemically, there is no difference between the richest Mexican beans and the wretchedest Tahitis, but to even a normal nose the difference is striking and immediate.
There is still much to be learned about the chemistry of vanilla. Its flavor is known to be due to natural vanillin, the chief flavoring principle of the plant, and to certain gums and resins, but of these last next to nothing is known. Yet if aptitude and experience still play the leading part in well-made extracts, chemistry without question takes the center of the stage in the adulterated ones.
Under the present law (1913), an extract may be sold as “extract of pure vanilla” if it is made of genuine vanilla beans; consequently “Mexican cuts,” “splits,” and rank Tahitis can be and are sold under this label; whereas some extracts, though strictly speaking not adulterated, are really worse than some adulterated ones. These “cheap vanillas” are made possible by the difference in cost between fine Mexican beans and poor defective ones, or beans of other growth; a matter, as a rule, of four or five dollars a pound; and are readily exposed by a comparative test in cookery or on the tongue.
—A common adulterant of cheap vanillas is artificial coumarin. Real coumarin is an aromatic crystalline substance found in the Tonka bean or cumaru. Tonka beans were formerly rampant in imitation vanillas, but their present high price, due to their use in cheap tobacco, has practically curtailed this activity. The Tonka, with its real coumarin, was bad enough—the theory has even advanced that hay fever is due to the presence in the air of coumarin from plants—but artificial coumarin, as flavoring, is worse. It is a powerful drug; a coal tar product, heart depressant and active poison.
Artificial vanillin produced by chemistry also is employed plentifully, not only in substitution but also for strengthening weak pure extracts. The real vanillin is one of the odorous principles of the vanilla bean, taking the form of tiny crystalline needles of hot bitter taste. It is imitated chemically by combining oxygen and eugenol, a colorless compound from oil of cloves, of bay, of cinnamon leaves, or of allspice; or by coniferin, a compound ether obtained from wood. Lacking the necessary gums and resins, it does not taste like real vanilla, and needless to say, its composition is not such as to inspire confidence.
Coumarin and vanillin are ordinarily used together in adulterating; the mixture is then sweetened and artificially colored, with prune juice added. This sometimes brings a substantial profit of 150 per cent to its manufacturer.
Fortunately detection of these subterfuges by simple means is not difficult. A suspected extract can be tested by holding a tablespoon of it over a lamp or other flame until about two-thirds of the liquid has evaporated; then, if on adding water to the remaining third until the spoon is full, the extract remains clear, undoubtedly it is not vanilla but an artificial product. Taste and smell, if one is familiar with true vanilla, are often test enough; coumarin in particular can be recognized by its odor, which is like that of Indian grass or “wood grass.”
The best test for the quality of vanilla is to pour a few drops on a lump of sugar, and then suck the extract through the lump. To determine the relative values of two or more extracts, a separate lump should be used for each. The distinction between good and bad will then be marked sharply. Finally, to avoid adulterated extracts, the label should be read carefully.
Owing to its refreshing aroma, convenience in use, and low cost, lemon extract holds popular favor as second to vanilla.
Extract of lemon is made by dissolving lemon oil, chiefly from skin of the fruit, in alcohol. To conform to the government standard, the compound must contain at least 5 per cent of the oil.
The world’s yearly yield of lemon oil is about two million pounds, of which southern Italy and Sicily produce the most, although there is some output from France and Spain. The best is shipped from Messina.
—Lemon trees flower in the summer, and the fruit is picked from November to February. As the oil from the later fruit has the richer color, many makers prefer it, but the earlier oil has the finer flavor.
Lemon oil is extracted most satisfactorily by washing and paring the lemon skin so that it comes off in one piece, and then pressing it against a clean sponge. The sponge absorbs the oil, and when full is squeezed into a container from which the oil is filtered and packed in sealed copper vessels, holding either ten or twenty-five pounds, for shipment.
In France the fruit is sometimes rolled about in vessels driven full of spikes, the oil running into a receptacle below. Another method is to press the whole fruit in a large vat, add water, and distill the resulting mixture. This has been tried in California, although without success, since the oil thus secured is very bitter, tasting strongly of turpentine.
—The oil is known to contain a large amount of terpenes or principles chemically like turpentine, which would account for such a taste or smell in a poor or stale product. These, with 6 to 10 per cent of citral, the chief flavor-giving constituent of lemon oil, would seem to identify the peculiar lemon taste; although there are certain unknown esters, or compound ethers, corresponding to the salts in metals, which also are taken to be factors of it. Citral is found in exactly the same form in limes, mandarins, and oranges.
Adulteration of lemon extract consists usually in either lowering the required amount of oil, or using in place of it citral, oil of lemon-grass, or some other natural oil containing citral. These substitutes naturally fail to give the true flavor, because they are lacking in terpenes, and presumably in the esters just mentioned. Many makers, to weaken the extract, lessen the alcohol; this indicates that their product cannot be made of lemon oil, because this will not dissolve in dilute alcohol. In most cases, weakened extracts are made of citral.
Terpenless lemon and orange extracts are made from lemon and orange oils from which the terpenes have been removed. They are much in favor among makers of low-grade flavors because they are soluble in very weak alcohol, and because considerably less oil is needed to make the extract. On account of the removal of the terpenes, the flavor is of course quite different from that of the true oils.
Using stale lemon oil in extract is not against the law, but no one is likely to buy more than once a product so compounded, for its foul taste of turpentine will ruin any cooking in which the extract is used.
To test lemon extract a little should be poured from the bottle, the cork replaced, and the bottle shaken for a few seconds. If the bubbles disappear at once, there is no water in the extract, and it is probably pure. If they disappear slowly, there is water in it, and the extract can contain no lemon oil. Or a teaspoonful of the extract may be added to a glass of water; if small drops of oil come to the surface, and the water, on standing, becomes cloudy, the extract is probably pure. But if the extract dissolves immediately, leaving the water clear, it is not pure, and contains no lemon oil.
No adulterated extract of any kind is really cheap. It is an actual fact that in a test of an adulterated lemon extract against a pure one costing twice as much, the pure one at but double the cost was found to be ten times as strong, in addition, of course, to its having by far the better flavor.
—Like lemon, orange extract must contain at least 5 per cent of the fruit oil. The only chemical difference between orange and lemon oil is that the former has an infinitely small proportion of flavoring esters not found in lemon. The two fruits are grown in the same countries and in the same way, the methods of producing the two oils are identical, and the tests for the adulteration of the one extract hold good for the other.
—Raspberry, strawberry, cherry, apple, pineapple, banana, and other familiar fruit flavors constitute a class of flavoring extracts similar in character and similarly made. They can be derived from their respective fruits, although previous to 1911 this was thought impossible. Up to that time, imitation extracts had been compounded chemically from coal tar ethers and esters, and ether was added often to give them pungency. They all tasted alike and none of them tasted like any fruit. One difficulty in making real fruit extracts was the lack of the essential oils in the several fruits; another, the change brought about in the delicate esters, the cause of the flavor, by cooking, since great heat destroys them. Pure fruit extracts are in every way immeasurably superior to the old unwholesome and unhealthful ether preparations, of which purchasers should beware. Fruit flavors labeled artificial or imitation are of the type; if not labeled, they can be detected by the odor of ether rising when the cork is drawn.