Brazil was the first country in the world to establish a formal system for grading and classifying green beans. In 1836, Dom Pedro II signed a bill into law that created three categories for green coffee: First Sort, Second Sort, and everything else. The law categorised the coffee according to its quantity of green bean defects — an approach that has continued until the present day.
From 1910 onwards, traders also began cupping samples and classifying coffees by sensory quality as well as by the number of defects — an approach that remains rare outside of Brazil and some African countries (Feria-Morales 2002). The Brazilian system for grading coffees continued to develop by consensus between coffee traders and warehouses, eventually becoming known as the Brazilian Official Classification (Classificação Oficial Brasileira, or COB). Because the system evolved over time in an unstructured way, some descriptors remain vague or open to interpretation (Ferraresso 2019).
The COB protocols were first formalised by the Brazilian Ministry of Agriculture (MAPA) in 2002. The COB is closely linked to the Green Coffee Association of New York’s classification system, which is used for trading on commodity exchanges but is not identical. While Brazilian coffee must be classified under the COB in order to be commercialised, producers and exporters are increasingly using other grading systems to communicate coffee quality, including the Brazilian Coffee Industry Association’s Coffee Quality Program and the SCA grading system for specialty coffee (Carvalho et al 2014).
According to the COB protocol, samples for grading should be taken at random from a number of bags in the warehouse that represent at least 10% of the lot. The samples are mixed together, and physical grading is based on a 300-gram subsample, while sensory analysis is based on a tasting of seven cups. The lot is primarily graded by ‘Category’ (size and shape of the bean); ‘Group’ (sensory quality); ‘Class’ (bean colour); and ‘Type’ (presence of defects) (MAPA 2003).