The most abundant CGA isomer was 5-CQA, which accounted for 69–74% of total CGA in all coffee brew extracts, especially those from green beans. The range of differences among samples sourced from five regions was relatively small. The 5-CQA content decreased >85% in coffee brews prepared from dark roasted beans compared with those prepared from non-roasted green beans derived from the same region. For example, the total CGA content in coffee brew extracts of light-, medium- and dark-roasted Sumatran beans decreased to 35.60%, 62.91%, and 80.60%, respectively, compared with the original CGA content in green beans. The 3-CQA and 4-CQA contents were higher in brews prepared from light-roasted, compared with green beans. This has been attributed to acyl migration via the formation of an ortho-ester intermediate (Deshpande, Jaiswal, Matei, & Kuhnert, 2014; Moon, Yoo, & Shibamoto, 2009).