The next operation is called clarifying. For this purpose the juice is conducted, along a wooden gutter lined with lead, to a place called the boiling house, where it is received into copper pans, or caldrons, each placed over a separate fire. A certain proportion of powdered lime is now added to it, for the purpose of taking up any acid which the juice may happen to contain. The heat is then increased until the liquor is nearly in a boiling state. By this process the greatest part of the impurities that were contained in the juice rise to the surface in a scum. The purified liquor is then carefully drawn off, either by a syphon or a cock, leaving the scum at the bottom of the pan.
From these pans it is conveyed, by another gutter, or channel, to the grand copper, or evaporating boiler, where the scum, which rises to the surface, is skimmed off as the liquor boils. After undergoing a similar process in smaller boilers, with a farther mixture of lime, until it has attained a certain degree of thickness, it is transferred into a large shallow wooden vessel, where, as it cools, it granulates or runs into an imperfect crystallization, by which it is in some degree separated from the molasses or treacle, an impure part of the juice, which is incapable of being crystallized, and which, in large casks, is exported, for various useful purposes, to the different countries of Europe.
From the cooler the sugar is removed to the curing-house. This is a large, airy building, furnished with a capacious cistern, for the reception of the molasses. Over the cistern is an open frame of strong joist-work; upon which are placed several empty hogsheads, each open at the head, and having a few holes at the bottom, closed by stalks of the plantain tree thrust through them. The mass of saccharine matter is now put into these hogsheads; the molasses are separated from the sugar, by draining, into the cistern, through the spongy stalks of the plantain; and the remainder, thus entirely crystallized, has the name of muscovado or raw sugar.
The article denominated clayed sugar undergoes a process somewhat different. For the preparation of this, the sugar, when taken from the coolers, is put into conical vessels of earthen-ware, each having, at its bottom, a hole, about half an inch in diameter, which, at the commencement of the process, is stopped with a plug. This plug, after the sugar has become perfectly cool, is removed, and the molasses drain through the hole. When these have ceased to run, the surface of the sugar, in the vessel, is covered with fine clay, to a certain thickness, and water is poured upon the clay. This, oozing through it, pervades the whole mass of sugar, re-dissolves the molasses still remaining in it, with some parts of the sugar itself, carries these off through the hole at the bottom, and renders the sugar, that is left, much purer than that which is made the other way.
The further refining of sugar, or forming it into the white conical loaves which are so much used in this country, is the business of the European sugar-bakers. This is done by dissolving the raw sugar in water, boiling the solution in lime water; and then clarifying it with bullock's blood, or the white of eggs, and straining it through woollen bags. After due evaporation it is suffered to cool to a certain degree. It is then poured into conical moulds of unglazed earthen-ware, the summits of which are perforated. Here it concretes into a hard white mass, leaving that part of the syrup, which will not crystallize, to run off through the hole in the point of the cone. The broad end of the cone is then covered with moist clay, the water from which penetrates into the sugar, and displaces and carries off the impurities which, otherwise, would be retained in and discolour it. It is then carefully dried, and receives the name of loaf, or lump sugar.
Sugar-candy is formed by boiling down a solution of sugar till it becomes thick; and then removing it into a very hot room, to crystallize upon sticks or strings, placed across small tubs, or other vessels. It is denominated brown or white sugar-candy, according to the quality of the sugar of which it is made.
Barley sugar is sugar boiled in barley water, but now more frequently in common water, till it is brittle. It is then rolled on a stone anointed with oil of sweet almonds, and formed into twisted sticks. To give it a colour, a small quantity of saffron is sometimes mixed with it.
When sugar was first introduced into this country, it was employed only as a medicine; but it has now become an essential article both of luxury and use. It is the basis of syrups; and is used in cooking, and in confections, preserves, sweetmeats, and liqueurs of every description. Sugar is also sometimes employed in medicine.
The juice of the sugar-cane is so palatable, and at the same time so nutritive, that, during the sugar harvest, every creature which partakes freely of it, whether man or animal, appears to derive health and vigour from its use. The meagre and sickly negroes exhibit, at this season, a surprising alteration; they now become fat and healthy. The labouring horses, oxen, and mules, being allowed, almost without restraint, to eat of the refuse plants, and of the scummings from the boiling-house, improve now infinitely more than they do at any other season of the year.
Rum is a spirituous liquor distilled from molasses, scummings of the hot cane juice from the boiling house, or raw cane liquor from canes expressed for that purpose, lees (or, as it is called in Jamaica, dunder), and water. The dunder answers the purpose of yeast for the fermentation.