The Coffee Science Foundation (CSF), supported by the Specialty Coffee Association (SCA), has partnered with the University of California, Davis (UC Davis) to launch a new research initiative focused on developing a more scientifically rigorous approach to assessing defects in green coffee.

Defects in green coffee can significantly impact the quality, flavour and price of the final product. These defects can be categorised into primary defects (more serious, affecting taste and quality) and secondary defects (less severe but still undesirable). They can result from issues in growing, harvesting, processing and storage.

The announcement follows a similar research initiative on green coffee defects launched by CSF and Zurich University of Applied Sciences in Switzerland last month, which aims to evaluate defects listed in the SCA Green Coffee Classification System and the Coffee Value Assessment.

The newly announced initiative at UC Davis will complement this work by examining how specific defects – such as partial black beans, chipped or broken beans and minor insect damage – affect the sensory qualities of brewed coffee. According to SCA, current classification standards are primarily based on tradition rather than sensory science, and this research seeks to address that gap by incorporating a more "scientifically grounded approach".

William Ristenpart, director at the UC Davis Coffee Center, said: “Coffee today is scored by exacting physical defect standards, but there is little understanding of how those standards were actually developed historically. For example, why are five chipped beans judged to be equivalent to one fully black bean? Why not four or six?”

Peter Giuliano, executive director of the CSF, added: "The UC Davis Coffee Center has extensive experience in both post-harvest processing and sensory detection, which are the key disciplines relevant to this research. We are excited to partner with them on this potentially transformative research."