What is the difference between heirloom and cultivar?

The distinction between these terms is a matter of human intervention versus natural evolution. A cultivar (short for 'cultivated variety') is a plant population selected by humans for specific, stable traits—such as yield, disease resistance, or cup profile—and propagated through controlled means. Most of the global coffee industry relies on a narrow genetic bottleneck of cultivars like Typica and Bourbon, which were historically isolated and spread from Yemen. Conversely, 'heirloom' is a term of convenience, not science. It is most frequently applied to Ethiopian coffee, where thousands of indigenous landraces—wild, naturally occurring populations—grow in forest environments. Because these plants have adapted to local microclimates over centuries without formal human breeding, they possess immense genetic diversity. When a producer or exporter labels a bag as 'heirloom,' they are often signaling that the lot is a mixture of these diverse, unidentified plants rather than a single, uniform cultivar. This creates a significant challenge for traceability; while a farmer growing a specific cultivar knows exactly what to expect in terms of harvest timing and disease susceptibility, a farmer managing heirloom trees is often working with a complex, heterogeneous population. The industry is slowly moving away from the 'heirloom' label as research institutions like the Jimma Agricultural Research Centre (JARC) and World Coffee Research continue to isolate and identify specific, high-performing varieties within these wild populations, such as the numbered JARC selections or named landraces like Kurume and Wolisho.