Special care should be exercised in ascribing the cause of damage to this commodity, particularly in the case of alleged water or moisture damage.
If not dry to the point at which it is in equilibrium with the relative humidity of the atmosphere, sugar may continue to lose moisture in storage, stowage, etc., dry and tend to cake. Similarly, if the sugar is too dry it will absorb moisture from the atmosphere until it attains equilibrium and if atmospheric conditions change and it dries again it will tend to cake. If the sugar is excessively dried it may suffer in luster and from dust formation. Sugar dried to equilibrium by the manufacturer will, if exposed to atmosphere of high humidity, i.e. in damp localities or during the voyage, inevitably re-absorb moisture to the higher level of the surrounding atmosphere.
The absorption or loss of moisture after leaving the manufacturers' premises will not be apparent until there is a further change in the relative humidity of the atmosphere. For instance, sugar which has been packed in a relative humidity of 65%. may well await shipment in a relative humidity of 85% and will come to equilibrium with the atmosphere, and to all intents and purposes, sugar will appear to be unaffected. After loading into the vessel, however, the relative humidity of the atmosphere may fall to 65% and under these circumstances the sugar will lose moisture. During this process it will dry and cake.
A relative humidity of between 80% and 85% is what one can consider as a critical relative humidity for sugar. Above this humidity sugar always tends to gain moisture very rapidly, while below it, it remains relatively unaffected. Even although the sugar gains moisture rapidly above 80% to 85% R.H., the first effect of the gain is merely to increase the moisture content and does not produce caking. A subsequent fall in humidity will, however, tend to dry the sugar out and will inevitably produce caking and lumpiness throughout the whole as the dissolved sugar on the outside of the crystals adheres to its neighbor.
When damaged by fresh or salt water, sugar should not be considered a total loss, as the quantity remaining after drainage should show little loss in polarization; sugar remaining after draining should show a greater degree of polarization than when wet. Cases have been known where sugar which had been totally submerged showed only a small loss in polarization. If local facilities are available for re-refining, it is in the best interests of all concerned to have the damaged sugar forwarded immediately to the refinery for re-elaboration and centrifugation. If the damaged sugar is landed at a port of distress, where no immediate facilities for reconditioning the sugar are available, it is sometimes advisable to have the sugar forwarded promptly to its destination. Damaged sugar may commence to deteriorate within a short time of the accident. The possibility of further damage arising due to fermentation and other factors during transit should also receive attention. Damaged sugar which has been rendered unfit for normal consumption may sometimes be used in the manufacture of cheap confectionery. A market for burnt sugar may be found for brewing purposes.
When examining sugar the following points should be borne in mind:
(a) Surveyors should refrain from expressing an opinion as to the cause of the damage unless there is clear evidence to support such opinion, e.g. rain during discharge, etc.
(b) Where samples are tested for the presence of seawater and the reaction is negative, the analyst should state this fact; where the reaction is positive, the analyst should specify the salts found. The analyst should not attempt to specify a cause, such as fresh water, rain water, seawater, etc. It is desirable that a sound sample, both of wrapping and contents, should be similarly tested.
(c) It is essential that the condition of the goods should be described in fullest detail and all possible inquiries made in an endeavor to establish the cause of any alleged damage.
(d) If foreign matter is found the analyst should state whether it is of an injurious character or otherwise. Wherever possible the analyst should carry out a polarization test.
(e) Sugar kept in damp storage is liable to inversion due to mold growth on the bags.
(f) Cane Sugar (unrefined) - At the end of each crop season quite large quantities of sweated sugar (due to lying in storage) are found. This might readily be mistaken for damage in transit.
(g) Raw Sugar - Liable to liquefy and leak from containers.
- Commodity Name: