Sago, a form of starch obtained from the trunks of several species of palm. Sagu (also written zagu and saga) is the Malay name for the starch and the tree which yields it, and is in Java the name for bread prepared from the farina. It was formerly supposed that sago was the product of cycas revoluta, a palm-like tree belonging to a very different family, which is even mentioned in some recent works as its source, and the tree is still to be found in greenhouse collections as the "sago palm;" while its trunk contains starch, it affords none of the sago of commerce. Several of the palms, especially those which flower but once, accumulate in the tissues of their trunks a large amount of starch, as a preparation for the nourishment of the future flower and fruit; and in countries where palms abound, the inhabitants make use of this as food, while it is not known in commerce. (See Palm.) The sago of the shops is mainly produced by sagus loevis, the smooth, and S. Rurnphii, the prickly sago palm, both natives of the islands of the Indian archipelago and other islands of that part of the world; the smooth species grows from 25 to 50 ft. high, while the other, which mainly differs in having its leaf stalks and the spathe or sheath to the flower cluster armed with sharp prickles, is rarely over 30 ft.
Both have graceful crowns of large pinnate leaves, and a one-seeded fruit an inch and a half in diameter, covered with shining reversed scales. Left to themselves, the trees attain their full growth in about 15 years, flower, produce their fruit, which is about three years in coming to perfection, and then die. To obtain the sago, the trees are felled as soon as they show signs of flowering; it is often stated that the starch is obtained from the pith of the trees, but palms have no true pith, and the starch, accumulated to nourish the fruit, is found to be deposited all through the tissues of the trunk, except in the hard rind; when allowed to bear fruit, the trunk finally becomes a nearly hollow shell. The trunk is cut into convenient lengths, which are split in halves, and the interior soft portion is scraped out and pounded in successive waters until all the starch is separated; the water in which the starch is suspended is allowed to stand until this settles, and the fibrous matter, which floats, is poured off with the water. The sediment is repeatedly washed, and when freed of all extraneous matter it is dried, and is then called sago meal.
In this form it is but little known in this country, that which is imported being consumed in manufacturing processes; it is the crude starch of the palm. The form in which sago is usually seen is that called granulated or pearl sago; the wet starch is dried, broken up, and pounded and sifted until of a somewhat regular size, the larger grains being of the size of mustard seed, intermixed with numerous smaller ones; the process of granulation is not known in full, but it is said that heat and mutual attrition by rubbing in a bag are used to form and shape the grains. Sago meal, the unprepared starch, presents under the microscope a great many muller-shaped granules, i. e., elongated, rounded at one end and truncate at the other; the granules of pearl sago are larger and less regular, being changed by the heat used in preparing it. Sago is usually of a pinkish or slightly brownish tint, but it is sometimes artificially bleached and pure white; it swells up in cold water, and does not completely dissolve by boiling. It has the general properties of other amylaceous foods, and is principally eaten in the form of sago pudding.
A factitious sago is sometimes met with, in which the grains are much larger and more regular than in the true, and of a pure white; this is made from potato starch, and may be readily detected under the microscope, as the potato starch granules are much larger than those of sago and of a different shape.
Sago Palm (Sagus Rumphii).