A good espresso blend is designed, not mixed. Each component does something specific.
The base
50 to 70%, usually a Brazilian or a washed Central American.
Its job is body, sweetness and chocolate — the foundation everything else sits on. It is chosen for reliability and availability as much as for character.
The brightener
20 to 40%, often an African washed coffee — Ethiopian, Kenyan, Burundian.
Its job is acidity and aromatics, to stop the blend being flat. Too much and the espresso becomes sharp and thin; milk drinks suffer first.
The accent
0 to 20%, optional. A natural process for fruit, an Indian or Indonesian for earthiness and body, or a fine robusta for crema and a bitter backbone.
Traditional Italian blends use 10 to 20% robusta for exactly this.
Pre-blend or post-blend
Post-blend — roasting each component separately and combining afterwards — lets each be roasted to its own optimum. More work, better results.
Pre-blend roasts them together. Simpler, and compromises on beans of different density and moisture.
Designing your own
Start with a base you like. Add a second coffee at 25% and taste against the base alone. Change one component at a time.
Blend after roasting, and weigh. It is more interesting than it sounds and it teaches you what each origin actually contributes.
Last reviewed 8 August 2026