How is the quality of cocoa checked - by hand, by machine?

The quality of cocoa is checked through sampling. The sampler selects at random a significant percentage of the bags for inspection and a stabbing iron is used to draw a number of beans from the selected bags. Or, if the cocoa is in bulk, samples are taken at random from the beans as they enter a hopper or as they are spread on tarpaulins. Different authorities may set a differing level of beans/samples for inspection. The International Standard recommends that the samples should amount to not less than 300 beans for every tonne of cocoa. For bagged cocoa, samples should be taken from not less than 30% of the bags, and for bulk cocoa there should be not less than 5 samplings per tonne.

The samples are analysed using the cut test. Most exporting countries' authorities specify standards dependent on the International Standards Organization cut test, as do normal physical cocoa contracts. The cut test provides an assessment of the beans from which analysts may infer certain characteristics of the cocoa, which gives an indication of quality. The cut test involves counting off 300 beans. These 300 beans are then cut
lengthwise through the middle and examined. Separate counts are made of the number of beans which are defective in that they are mouldy, slaty, insect damaged, germinated or flat. The results for each kind of defect are expressed as a percentage of the 300 beans examined. The amount of defective beans revealed in the cut test gives manufacturers an indication of the flavour characteristics of the beans. Bean counts are another measure of quality that producing countries often use, though there is no internationally accepted bean size classification. The Federation of Cocoa Commerce defines the following method for bean counts: A sample of not less than 600 grammes of whole beans, irrespective of size but not including flat beans, will be counted to obtain the number of beans per 100 grammes.

Further tests are carried out by chocolate manufacturers and cocoa processors, particularly for beans from origins that are inconsistent in quality or prone to off flavours. The manufacturer cannot sift out all the defective beans and so must ensure good quality at the selection stage. Consistency in quality for the production of cocoa mass cannot be achieved when using one source of cocoa beans because of the large natural variability which exists in each lot. The differences can be reduced by having a number of different types and lots of cocoa beans of known quality in stock and making an appropriate blend. Strict control of the roasting and alkalising processes is also required to produce the best quality.

For the chocolate manufacturer the yield of nib is very important, as is the amount of cocoa butter in the nib. Higher levels of cocoa butter mean that lower levels will need to be added later on in the manufacturing process. Nib yields are determined in the laboratory. Flavour is also important for chocolate manufacturers. Flavour assessment is normally carried out by panels of between five and ten experienced tasters. Off flavours can readily be detected by tasting roasted ground nib of cocoa liquor directly or they can be mixed with sugar and water to make a basic dark chocolate before tasting. Mouldy and smoky off flavours and excessive bitterness cannot be removed during processing. Acid tastes can be altered in processing through neutralisation. Sub standard beans can be pressed whole to produce expelled cocoa butter which is then refined. Better quality beans are deshelled before pressing to produce pure pressed cocoa butter and cocoa press cake (which ultimately becomes cocoa powder). Chocolate manufacturers have a number of requirements with respect to the quality of cocoa butter: hardness, melting and solidification behaviour.

Cocoa trade associations and national authorities produce standards or gradings for cocoa beans covering the bean count per 100g and the
percentage of permitted faults, moisture and foreign matter, and the International Standards Organization provides a specification for cocoa
beans