Post-harvest Processing and Quality Assurance for Speciality/Organic Coffee Products

This paper covers the post-harvest aspects, processing and quality assurance for speciality/organic coffee products. It starts with the origins of coffee, what aspects provide inherent quality, and diseases that deter quality. It then touches on coffee harvesting, the timing for harvesting and development of fruit color. It discusses picking systems, both manual and mechanical and their effects on quality. It discusses coffee processing, both the dry and wet methods. The dry method involves sorting, cleaning and winnowing, flotation sun-drying and mechanical drying. The wet method, yielding ‘washed’ or ‘mild’ coffee, involves pulp removal, into flesh, skin and beans. Then separation into mature and immature beans, followed by fermentation, washing and drying. The effects of over and under-drying on quality are discussed. Hulling to remove dry flesh and parchment, then optional polishing is mentioned. The importance of grading, sorting and storage, as well as bagging and export, are covered. Further processing includes blending, roasting and cooling. The pyrolysis and color development effects of roasting by drum or hot air roasting; then cooling by water or air methods are discussed. Critical storage issues are described, followed by grinding and brewing and further quality aspects of coffee.