Fermenting
I allow myself the pleasure of thinking that I am causing some of my readers a little surprise when I tell them that cacao is fermented, and that the fermentation produces alcohol. As I mentioned above, the cacao bean is covered with a fruity pulp. The bean as it comes from the pod is moist, whilst the pulp is full of juice. It would be impossible to convey it to Europe in this condition; it would decompose, and, when it reached its destination, would be worthless. In order that a product can be handled commercially it is desirable to have it in such a condition that it does not change, and thus with cacao it becomes necessary to get rid of the pulp, and, whilst this may be done by washing or simply by drying, experience has shown that the finest and driest product is obtained when the drying is preceded by fermentation. Just as broken grapes will ferment, so will the fruity pulp of the cacao bean. Present day fermentaries are simply convenient places for storing the cacao whilst the process goes on. In the process of fermentation, Dr. Chittenden says the beans are “stewed in their own juice.” This may be expressed less picturesquely but more accurately by saying the beans are warmed by the heat of their own fermenting pulp, from which they absorb liquid.
In Trinidad the cacao which the girls have scooped out into the baskets is emptied into larger baskets, two of which are “crooked” on a mule’s back, and carried thus to the fermentary. In Surinam it is conveyed by boat, and in San Thomé by trucks, which run on Decauville railways.
The period of fermentation and the receptacle to hold the cacao vary from country to country. With cacao of the criollo type only one or two days fermentation is required, and as a result, in Ecuador and Ceylon, the cacao is simply put in heaps on a suitable floor. In Trinidad and the majority of other cacao-producing areas, where the forastero variety predominates, from five to nine days are required. The cacao is put into the “sweat” boxes and covered with banana or plantain leaves to keep in the heat. The boxes may measure four feet each way and be made of sweet-smelling cedar wood. As is usual with fermentation, the temperature begins to rise, and if you thrust your hands into the fermenting beans you find they are as hot and mucilaginous as a poultice.
| Time. | Temperature. | |
| When put in | 25° C. or 77° F. | |
| After 1 day | 30° C. or 89° F. | |
| After 2 days | 37° C. or 98° F. | |
| After 3 days | 47° C. or 115° F. | |
| (After the third day the heat is maintained, but the temperature rises very little.) | ||
The temperature is the simplest guide to the amount of fermentation taking place, and the uniformity of the temperature in all parts of the mass is desirable, as showing that all parts are fermenting evenly. The cacao is usually shovelled from one box to another every one or two days. The chief object of this operation is to mix the cacao and prevent merely local fermentation. To make mixing easy one ingenious planter uses a cylindrical vessel which can be turned about on its axis.
In other places, for example in Java, the boxes are arranged as a series of steps, so that the cacao is transferred with little labour from the higher to the lower. In San Thomé the cacao is placed on the plantation direct into trucks, which are covered with plaintain leaves, and run on rails through the plantation right into the fermentary. Some day some enterprising firm will build a fermentary in portable sections easily erected, and with some simple mechanical mixer to replace the present laborious method of turning the beans by manual labour.
The general conditions1 for a good fermentation are:
The mass of beans must be kept warm.
The mass of beans must be moist, but not sodden.
In the later stages there must be sufficient air.
The boxes must be kept clean.