As the manufacture of soap from waste vegetable bases represents something entirely new, so do the actual methods of production. The revolution is complete. In preparing the conventional soap from 10 to 16 days are necessary. By the new process the cereal soap can be made in sixty minutes! Furthermore, the operation is clean, absolutely free from odour, and cold, no heat whatever being required, except to warm the factory during the winter for the comfort of the employees. The machinery necessary is also of the simplest and most inexpensive character. Under these conditions there is not only a very marked saving in time, but of fuel and labour. In these high-pressure days wastage of time is as criminal as the wastage of material, and one logically asks why spend ten days in consummating a specific end when one hour will suffice for the purpose?
The saving in capital expenditure is very impressive, being at least 75 per cent. below that demanded for equipping the conventional factory. In other words, £10,000—$50,000—will provide an installation capable of turning out as much cereal soap as could be recorded with a plant costing £40,000—$200,000—devoted to the orthodox system.
The outstanding feature of the process is the complete absence of all boiling operations. The starch and protein-yielding material are passed through a mill to be reduced to a fine powder of the consistency of flour. This being a straightforward milling operation, the machinery ordinarily employed for grinding grain and other foods may be used. The flour is then emptied into a mixing machine, which is naught but the familiar dough-mixer used in the bakery. When the mixer is set in motion the caustic soda is admitted in a fine controlled stream. Directly the two materials come into contact the chemical reaction commences, the soda attacking the starch granules and breaking them down. Evidence of the battle in progress between the two chemicals is betrayed by the emission of the strong ammonia fumes, which prove that the nitrogenous compounds are being released. The admission of caustic soda is continued until the chemical reaction is concluded and the starch granules have been completely broken up. As the process is advanced the vegetable oil is admitted, the operation being so controlled as to yield a plastic mass of predetermined consistency. This is thoroughly kneaded after the manner of baker’s dough. The subsequent processes are common to those of the ordinary soap manufactory, the material being passed successively through the milling, plodding, and stamping machines.
The raw materials for the provision of the essential protein are drawn from the extensive vegetable kingdom. But in no instance is any material having a claim upon the community or the animal world as a possible food used for the purpose. Dependence is placed rather upon the waste incurred by the preparation of other products, or of materials which have been condemned as useless for food purposes.
As a case in point it may be mentioned that a grain-carrying ship was torpedoed, sunk, and, together with the cargo, subsequently salvaged. The retrieved grain was dried in the anticipation that it might be found suitable for cattle-feeding. But the expectations were doomed to disappointment. The wheat had been too completely impregnated with the salt from the sea. No other profitable use presenting itself, it was acquired for conversion into soap. It was ground in the usual manner and turned into the mixer. The presence of the salt, which had rendered the grain useless even as a cattle food, did not constitute an adverse factor. Had it not been for the cereal soap factory this cargo would have had to suffer destruction and have been completely lost to the community, whereas it was sold at a remunerative figure. Potato flour has likewise been utilized, but has not been widely exploited for the simple reason that this material constitutes an excellent foodstuff, either for man in the form of farina, or for cattle. Maize has also been used together with such products as rice, barley, oats, rye, and so on, but, except where the produce of this nature has suffered injury, it is not turned into soap. However, in those countries where a heavy surplus of such crops is encountered it would be found profitable to establish the cereal soap industry as a means of turning the glut to profitable advantage.
The principle governing the selection of the starch-yielding constituent is also observed in regard to the fat which is necessary. This is drawn exclusively from the margarine factories. It is a residue and at the moment possesses no other known marketable value. The ability to turn this refuse into an ingredient for soap has come as a distinct relief to the margarine industry, which threatened to be perplexed in the economical disposal of the accumulations. Seeing that the margarine manufacture is progressing by leaps and bounds, there is not likely to be any shortage in connection with the fat constituent of the cereal soap.
Supplies of a cheap and useless albeit rich starch waste product have also been secured in illimitable quantities. This has materially simplified the task of production. While a certain proportion of this particular raw material is secured for the preparation of an article of food, about 75 per cent. is discarded as waste. Since cattle will not eat it there remains no other field of utilization beyond the soap factory, for which it is eminently suited. In addition to the above-mentioned quantities ample supplies of this material are forthcoming, because it is freely used as ballast in ships sailing from the corner of the world in which the plant grows in profusion. Should the demand for the food product which this substance yields increase it would not exercise any stringency, because the offal alone would be adequate to satisfy soap-making requirements. In pre-war days this waste cost only 10s.—$2.50—per ton, but during the war, owing to freight inflation, the price rose to £10—$50—per ton, while little was carried in ballast, more profitable cargo being readily obtainable. Consequently imports declined, only sufficient being brought into the country to furnish the needs of the industry from which the foodstuff is made. But the vegetable world is wide, and so it is by no means a difficult problem to satisfy requirements for this new industry, even in regard to starch-yielding wastes. The only other essential ingredient is soda. As enormous quantities of this article are manufactured in this country supplies thereof are readily assured and at an attractive figure.
There is one feature concerning this conversion of vegetable wastes into soap which deserves mention. Should all familiar starch-yielding products become unobtainable, a remote contingency, or attain an excessive figure, manufacture need not be suspended. As a last extremity sawdust can be utilized as the protein base. The possibility of turning sawdust into soap constitutes something distinctly new and novel to the industry, but the apparently impossible is readily feasible under the process described. Normally such an expedient would not find favour, inasmuch as certain difficulty is experienced in the complete subjugation, or elimination, of the fibre which is exceedingly resistant to the breaking-up action resulting from milling and the chemical reaction. Nevertheless, the circumstance that sawdust can be used in this connection opens up vast possibilities, and represents an opportunity for inventive effort in the perfection of simple and completely effective means to overcome the fibre difficulty.
So far as industry is concerned the use of nitrogenous and oil wastes in the form of soap has enabled startling economies to be effected. In the woollen industry alone the saving in the soap-bill ranges from 20 per cent. upwards, as compared with other soaps which have been used, while the silk and cotton crafts can point to like economies. The successful subjugation of the lime-soap fiend is beneficially reflected in other directions. The effluents from the factories are conducted into the local drainage systems. The presence of the lime-soap in the drains provokes a host of troubles, such as clogging of the pipes and the fouling of traps and gullies, the curds proving exasperatingly tenacious and defying ready removal by ordinary flushing measures. Furthermore, the sludge reclaimed from the sewage, if contaminated by lime-soap, suffers material depreciation as a fertilizing agent because the grease, which is eventually released from the lime, tends to clog the soil.
But the most impressive fact to the ordinary user, both domestic and industrial, is the opportunity to reduce the wastage of soap. The fat content of the cereal soap is 50 per cent. less than that of the familiar article, and the whole of this is free to emulsify, from its refusal to coagulate with the lime in the water. Moreover, it contains two cleansing agents—the soda and the nitrogenous compounds—whereas the rival carries only one—the soda. Therefore it is not surprising to learn that in actual practice one pound of cereal soap will go as far, and do as much useful work, as two pounds of the ordinary soap. The ability to make a lather in sea-water is another distinct advantage which has been responsible for the widespread use of this commodity in the Royal Navy and mercantile marine.