High-quality espresso almost always comes from high-altitude, single-origin Arabica - typically grown above 1,200 meters, on small-holder farms in places like Colombia, Ethiopia, or Guatemala.
High altitude slows the bean's maturation. The cherries ripen more gradually. Sugars develop more fully. Acid levels stay balanced. The result is a denser, more complex bean with a fuller flavor profile - exactly what espresso needs.
Most grocery store coffee - including most "espresso blends" - is made from mass-harvested commodity beans grown in lower elevations, blended together for consistency rather than character. Pull that as espresso and all the flatness gets concentrated.
Fabula's Espresso is single-origin Colombian Arabica, hand-picked at peak ripeness from shade-grown small-holder farms at over 1,400 meters. Top 1% specialty grade. No fillers, no commodity blend.