The next table shows the imports (expressed in English tons) into the United Kingdom in more recent years:
IMPORTS OF CACAO BUTTER.
| Year | 1912 | 1913 | 1914 | 1915 | 1916 | 1917 |
| Tons | 477 | 912 | 1512 | 599 | 962 | 675 |
The wholesale price of cacao butter has varied in the last six years from 1/3 per pound to 2/11 per pound, and was fixed in 1918 by the Food Controller at 1/6 per pound (retail price 2/- per pound). The control was removed in 1919, and immediately the wholesale price rose to 2/8 per pound.
Cacao Shell.
Although I have described cacao butter as a by-product, the only true by-product of the combined cocoa and chocolate industry is cacao shell. I explained in the previous chapter how it is separated from the roasted bean. As they come from the husking or winnowing machine, the larger fragments of shell resemble the shell of monkey-nuts (ground nuts or pea nuts), except that the cacao shells are thinner, more brittle and of a richer brown colour. The shell has a pleasant odour in which a little true cocoa aroma can be detected. The small pieces of shell look like bran, and, if the shell be powdered, the product is wonderfully like cocoa in appearance, though not in taste or smell. As the raw cacao bean contains on the average about twelve and a half per cent. of shell, it is evident that the world production must be considerable (about 36,000 tons a year), and since it is not legitimately employed in cocoa, the brains of inventors have been busy trying to find a use for it. In some industries the by-product has proved on investigation to be of greater value than the principal product—a good instance of this is glycerine as a by-product in soap manufacture—but no use for the husk or shell of cacao, which gives it any considerable commercial value, has yet been discovered. There are signs, however, that its possible uses are being considered and appreciated.
For years small quantities of cacao shell, under the name of "miserables," have been used in Ireland and other countries for producing a dilute infusion for drinking. Although this "cocoa tea" is not unpleasant, and has mild stimulating properties, it has never been popular, and even during the war, when it was widely advertised and sold in England under fancy names at fancy prices, it never had a large or enthusiastic body of consumers.
In normal times the cocoa manufacturer has no difficulty in disposing of his shell to cattle-food makers and others, but during 1915 when the train service was so defective, and transport by any other means almost impossible, the manufacturers of cocoa and chocolate were unable to get the shell away from their factories, and had large accumulations of it filling up valuable store space. In these circumstances they attempted to find a use near at hand. It was tried with moderate success as a fuel and a considerable quantity was burned in a special type of gas-producer intended for wood.
Cacao shell has a high nitrogenous content, and if burned yields about 67 lbs. of potassium carbonate per ton. In the Annual Report of the Experimental Farms in Canada, (1898, p. 151 and 1899, p. 851,) accounts are given of the use of cacao shell as a manure. The results given are encouraging, and experiments were made at Bournville. At first these were only moderately successful, because the shell is extremely stable and decomposes in the ground very slowly indeed. Then the head gardener tried hastening the decomposition by placing the shell in a heap, soaking with water and turning several times before use. In this way the shell was converted into a decomposing mass before being applied to the ground, and gave excellent results both as a manure and as a lightener of heavy soils.
On the Continent the small amount of cacao butter which the shell contains is extracted from it by volatile solvents. The "shell butter" so obtained is very inferior to ordinary cacao butter, and as usually put on the market, has an unpleasant taste, and an odour which reminds one faintly of an old tobacco-pipe. In this unrefined condition it is obviously unsuitable for edible purposes.