1. Flavour

Flavour is a key criterion of quality for manufacturers of cocoa products. The flavour criterion includes both the core attributes, including cacao intensity, together with any complementary flavour notes, and the absence of flavour defects.

Flavour is a key criterion of quality for manufacturers of cocoa products. The flavour criterion includes both the core attributes, including cacao (chocolate) intensity, together with any complementary flavour notes, and the absence of flavour defects. 

Defects include effects of under-fermentation, over- fermentation and taints. The cut-test, which is used in grading cocoa beans for the market, and is described in Appendix A, may give an indication of gross flavour defects, e.g. excessive bitterness and astringency from a high proportion of slaty beans, or mouldy/musty notes from mouldy or infested beans as well as putrid aromas alluding to over fermentation. Other than these examples, however, the cut test is not a reliable indicator of complete flavour quality.

To assess the flavour of a sample of cocoa beans it must be roasted and turned into either a course powder, cocoa mass or made into chocolate and tasted. This is usually done by a taste panel of between six to ten experienced tasters [1] . 

However, for particular applications, single expert tasters with many years’ experience can also be used effectively for detection of off-flavours and, providing that more tasting repetitions are carried out for increased statistical rigour, also for comprehensive flavour description. 

Cocoa mass tasting is routinely used in many factories to prevent the introduction of cocoa mass with off-flavours entering chocolate production lines. 

Cocoa mass samples can be tasted directly without the addition of cocoa butter, sugar and milk products which dilute the taste impression and impart flavour notes unrelated to the cocoa beans being tested.

Tasting of chocolates has some disadvantages since additional time is needed for the flavour to stabilise after the samples are prepared, and the samples do not keep as well as cocoa mass, either deep frozen or at ambient temperature.

Moreover, chocolate samples are often difficult to prepare to normal standards on the farms and estates where the beans are produced due to the need for processing equipment.

Samples can be evaluated for cacao intensity, residual acidity, bitterness and astringency characteristics which are normally present in cocoa mass and chocolates, as well as the presence of any off-flavours and any complementary flavours such as fruity or floral notes. The sensory evaluation methods and terminologies used by manufacturers and research institutions often vary. 

However, the recently published “Guide for the Assessment of Cacao Quality and Flavour” (Cacao of Excellence, 2023) aims to establish a common language for a clear communication throughout the cocoa value chain. 

This guide has been compiled by the Cacao of Excellence programme of the Alliance of Bioversity International and CIAT, in collaboration with the members of the Working Group on the development of the International Standards for the Assessment of Cacao Quality and Flavour (ISCQF). 

It contains a full set of protocols, established through consultation with industry and academic experts, to (1) sample the cocoa beans to be evaluated, (2) assess its physical quality, (3) process it into coarse powder, cocoa mass and chocolate and (4) carry out the sensory evaluation of these products. A summary of the protocols for the small-scale preparation of cocoa mass and chocolates, and their flavour evaluation, which were the basis of the ISCQF and have been used by the internationally recognised “Cacao of Excellence” and “Heirloom Cacao Preservation” initiatives are provided in Appendix B.

Additionally, the FCC has included an Optional Clause in its commercial contract rules – “Off Flavours in Cocoa Beans”. If the Parties have failed to agree upon the selection of an independent taste panel then CIRAD (Centre de coopération Internationale en Recherche Agronomique pour le Développement) will be appointed to undertake the independent assessment of the specific off flavours or, if CIRAD are unable to act, such other competent body as may be nominated by the Federation.

The inherent potential flavour of a particular source of cocoa beans is determined principally by the variety of the trees (see the CacaoNet Global Strategy for Conservation and Use of Cacao Genetic Resources (CacaoNet, 2012) for further details on cacao’s genetic diversity). 

Traditionally, the trade has considered there to be three main types, “Criollo”, “Forastero” and “Trinitario”. [2] The type of cacao historically grown in MesoAmerica and the circum-Caribbean region is known to the cocoa trade as “Criollo” (meaning native) and is characterised as having lightly pigmented beans which require little fermentation. The flavour is characterised as being delicate and sweet with caramel, honey and fresh hazelnut notes. “Forastero” (meaning foreign-from another part of the country) was the term originally used for the Amazonian types, which entered the trade as cocoa cultivation spread to other regions. 

Although a new nomenclature for the various Amazonian types based on their genetics has been proposed (Motomayor, et al., 2008, Zhang et al., 2012), the term “Forastero” is still used by the trade to refer to mainstream cocoas. These include those characterised as Lower Amazon Amelonado varieties, traditionally grown in West Africa, Brazil and Indonesia, and mixed hybrid varieties which often include one or more of the Upper Amazon genetic groups in their ancestry. 

“Forastero” cocoa is characterised by mid to dark purple beans which present a strong cacao intensity when properly fermented and processed. 

The term “Trinitario” (meaning native of Trinidad), although perhaps only originally applied to the hybrid populations between Criollo and Amazonian types occurring in Trinidad, has since been used to describe various hybrid types, which are now known in the trade for their floral/ fruity flavours. 

The Ecuadorian “Nacional” type, probably derived from a local Amazon population with some hybridisation with Trinitario types, is also known for its distinctive flavour characterised by floral and fresh nut notes.

It is important to note that there is considerable genetic diversity within each group, and that advancements in research continue to refine our understanding of the impact of genetics on flavour quality. Certain quality traits, including some flavour characteristics, have been shown to be heritable (Clapperton et al., 1994; Sukha et al., 2017) but most breeding work has focussed on yield and disease resistance traits, rather than flavour, particularly for varieties developed in West Africa and Southeast Asia. However, national programmes in some countries in Latin America and the Caribbean region have placed increasing emphasis on developing varieties with traditional flavours but with yields more comparable with more recently introduced clones (for example Loor et al., 2019). There are also initiatives to explore cacao genetic diversity for interesting flavour attributes (see pg 14) and to develop markers that may be useful in breeding for flavour attributes (for example Colonges et al., 2022).

Today, so called “fine flavour” cocoas represent approximately 12% of the total world crop (ICCO, 2023). Fine flavour cocoas are characterised by their exceptional flavour and aromatic qualities, and often associated with specific cacao varieties, regions, or genetic groups that produce cocoa beans with unique and desirable flavour profiles. These cocoas are required by some chocolate manufacturers who pay a premium for them. They are chiefly used in the manufacture of specialty and high cocoa solids chocolates, usually from a blend of different types of beans, to give a distinctive flavour profile to the finished chocolate. Careful post-harvest processing is needed to optimise the flavour attributes, and ensure the consistency in quality required, for farmers to obtain the premium prices needed to make growing such varieties economic.

Mainstream “Forastero” cocoa, such as many of the cocoas produced by Côte d’Ivoire, Ghana, Nigeria, Cameroon, Indonesia and Brazil, is sometimes referred to as “bulk” cocoa since it is produced and traded in large quantities for use in the production of mass-market chocolate, cocoa powder, cocoa butter and other cocoa-based products. The various mainstream cocoas, which are grown principally in West Africa and Brazil, are similar in that they possess a good, strong, cacao intensity with few pronounced complementary flavours. Although the planting materials may share a similar genetic background, differences in post-harvest processing may lead to variations in the level of cacao intensity, and in some cases the generation of off-flavours. These mainstream cocoas, when they are well prepared, are eminently suited to the manufacture of milk chocolate, which forms a major part of the global chocolate market. However, some high-yielding varieties contributing to mainstream cocoa supply, such as CCN51, need specific post-harvest processing practices to ensure they do not have off-flavours, which limit their use in chocolate production (see section 1.4).

There are indications that in addition to the effects of genetic background and post- harvest practices, the climate and soil may also contribute to flavour differences, referred to as the “terroir” effect as in wine production (Sukha D, Butler, Comissiong, & Umaharan, 2014). There are several recent initiatives which aim to recognise and celebrate the diversity of cocoa flavours which are the result of all of these factors, and to promote the linkages within the supply chain which will help reward those producing high quality cocoa:

• Heirloom Cacao Preservation Initiative 
  is a partnership between the Fine Chocolate Industry Association and USDA/ARS which aims to identify the finest flavoured cocoas, understand their genetic diversity and find ways to preserve them and reward the growers who cultivate them. 
  Further details can be found from the website: https://www.finechocolateindustry.org/ 
• Cacao of Excellence
  is an initiative supported by research institutions, chocolate manufacturers and cocoa organizations. It describes itself as a unique global platform discovering, convening, promoting and rewarding cacao producers of excellence from all producing origins for superior cacao quality and flavour diversity. Since 2009, Cacao of Excellence has been the entry point for cacao producers to participate in the Cacao of Excellence Awards, a prestigious global cacao competition that recognises the work of cacao farmers and celebrates the quality and flavour diversity of cacao produced around the world. National Organization Committees have been established in each of the participating countries to ensure that samples, of either commercial or experimental origin, are submitted for evaluation by panels of experts. 
  Further details are available from the website: www.cacaoofexcellence.org 
• MOCCA: Maximising Opportunities in Coffee and Cacao in the Americas 
  is an initiative funded by USDA and lead by Technoserve/Lutheran World Relief to help farmers grow their incomes through measures including technical support to improve post-harvest processing, facilitate supply of planting materials and facilitating access to higher value markets. 
  Further details are available from the website: https://mocca.org/en/

Whatever the genetic background of the trees producing the cocoa, the development of flavour is also dependent on correct fermentation and drying procedures, and further processing steps such as roasting, alkalisation or conching. 

All types of cocoas can suffer from several off-flavours and these are described below, along with the method of assessment or detection. The causes of the off-flavours, and guidance on good practices which can minimise them, are discussed in detail in Part III of this publication.