The mint should be cut as soon as it is in full bloom, and the lower leaves become sere; the first crop will not be fit to cut as early as the two succeeding ones. It is then to be hayed and put in cock, and is then ready for distillation.
I have consulted many mint growers, who have cultivated it for a series of years, in regard to the average yield per acre, and have arrived at the following estimate, which I think is low, provided the land is suitable, and is properly cultivated. I estimate the average yield per acre for the first year at 18 lbs.; the second year at 14 lbs.; and the third year at 8 lbs.—making the product for three years 40 lbs., which I think will not materially vary from the actual result, though growers aver they have raised from 30 to 40 lbs. per acre the first season.
Several years since, the only method of extracting the oil then known was by distilling the herb in a copper kettle, or boiler, and condensing in the usual manner; a slow and tedious process, by which about 12 or 15 pounds of oil could be separated in a day. But recently steam, that powerful agent, which has wrought such immense changes in our social and national economy, has been applied to this subject with its usual attendant success. The present method consists in the use of a common steam-boiler, of the capacity of from 100 to 150 gallons, from which the steam is conveyed by conductors into large wooden air-tight tubs, of 200 gallons capacity, containing the dried herb; from which it is conveyed, charged with the volatile principle of the plant, into a water-vat, containing the condenser. The water collected at the extremity of the condenser, although it does not readily commingle with the oil, is highly tinctured with it, and is used to feed the boiler. Two tubs are necessary, in order that when the "charge" is being worked off in one, the other can be refilled. The oil is then to be filtered, and is ready for market. The expense of a distillery is estimated at 150 dollars, which, with the labor of two men, and a cord of dry wood, will run 40 lbs. of oil per day. The usual price for distilling is 25 cents per pound.
The cost of production is of course greatly modified by circumstances. If grown on rich bottom lands, or prairie, unusually free from weeds and grass, the labor required will be comparatively trifling. From information derived from the principal mint growers in this vicinity, I have prepared the following estimate of the cost of production of an acre of mint for three years:—
| FIRST YEAR. | |
| Dollars. | |
| Rent of an acre of land one year | 8.00 |
| One day plough and drag, one hand and team | 2.00 |
| Half day furrowing, digging roots, one hand and horse | 1.00 |
| Three days planting, at 75 cents | 2.25 |
| Two days dressing with hoe, at 75 cents | 1.50 |
| Two days with cultivator and hoe, 1.00 | 2.00 |
| Two days with cultivator and hoe (third dressing) | 1.50 |
| One and a-half days cutting new mint, at 75 cents | 1.13 |
| Curing and drawing to distillery | 1.50 |
| Distilling 18 lbs. oil, at 25 cents | 4.50 |
| Can for oil | .25 |
| 25.63 | |
| SECOND YEAR. | |
| Rent of an acre of land one year | 8.00 |
| Cutting one acre of old mint | .75 |
| Curing and hauling to distillery | 1.50 |
| Distilling 14 lbs. oil, at 25 cents | 3.50 |
| Can for oil | .25 |
| 14.00 | |
| THIRD YEAR. | |
| Rent of an acre of land one year | 8.00 |
| Cutting, curing, &c. | 2.25 |
| Distilling 8 lbs. of oil, at 25 cents, and can | 2.25 |
| 12.50 | |
| Total expenses for three years | 52.13 |
| Forty pounds of oil, at dollars 1.37½ per pound | 55.00 |
| Deduct expenses | 52.13 |
| Net profit | 2.87 |
In the above estimate I have omitted the expense of roots, for the reason that the crop will yield as many as are required for planting. The price of roots is about 50 cents per square rod, and if they are in demand, the profit of the crop will be greatly enhanced by selling them at that, or even a lower price.
It will be readily perceived that the culture of peppermint promises no great return of profit in sections of country where land is valuable, and where the expense of production is nearly double what it is in newly-settled districts. It is a fact that in Michigan, and other Western States, the actual expense of production is about one-half less than the above estimate, and the yield is a fourth greater; the greater distance from market, which is usually New York city, not being taken into account, the freight on oil being comparatively trifling. Another consideration in favor of prairie cultivation is, that the mint will endure for years by simply ploughing over the surface every second year, which seems to invigorate the herb, and obviates the necessity of replanting every second or third year, as must be done in older settled localities."
In India the perfumed oils are obtained in the following manner:—The layers of the jasmine, or other flowers, four inches thick and two inches square, are laid on the ground and covered with layers of sesamum or any other oil yielding seed. These are laid about the same thickness as the flowers, over which a second layer of flowers like the fruit is placed. The seed is wetted with water, and the whole mass covered with a sheet, held down at the end and sides by weights, and allowed to remain for eighteen hours in this form. It is now fit for the mill, unless the perfume is desired to be very strong, when the faded flowers are removed and fresh ones put in their place. The seed thus impregnated is ground in the usual way in the mill and the oil expressed, having the scent of the flower. At Ghazipoor the jasmine and bela are chiefly employed; the oil is kept in the dubbers, and sold for about 4s. a seer.
The newest oils afford the finest perfume. In Europe a fixed oil, usually that of the bean or morerja nut, is employed. Cotton is soaked in this, and laid over layers of flowers, the oil being squeezed out so soon as impregnated with perfume. Dr. Johnson thus describes the culture and manufacture:—