Light and Medium Roast: How Roasting Shapes Our Coffees

Roasting turns a green coffee seed into something you can brew, and how far it goes decides much of what reaches the cup. A light roast stops early and keeps more of the coffee's own aromatics and acidity; a medium roast goes further, rounding the acidity and building sweetness and body. Our Caldas Geisha Harmony is roasted light, and Nariño Sweet Symphony, Tropical Dulce Dream and Caldas Serenity Now are medium roasts.

What happens in the roaster

Green coffee is hard, pale and grassy-smelling. In the drum, it dries, turns yellow, then brown, and starts to give off the smell of bread and toasted sugar as Maillard reactions and caramelization build new aromas. Partway through, the beans crack audibly as moisture and gas escape, a moment roasters call first crack. A light roast is taken out not long after it. A medium roast stays in a little longer, to a deeper brown, before the second crack and the oils that come with darker roasts.

None of this changes where a coffee grew. It decides which part of that coffee you taste most clearly.

Light: keeping the delicate notes

A light roast tends to keep the bright acidity and the floral and fruit aromatics that longer roasting would mute. That is the reason we roast Caldas Geisha Harmony light: its chamomile-like florals and juicy citrus are the point of the coffee, and a darker roast would trade them for roast character. Light roasts usually show best as a pour-over, taken black.

Medium: sweetness and body

A medium roast tends to round the acidity and bring sweetness, body and depth forward, while keeping the coffee's own character recognizable. It suits coffees whose strength is sweetness:

• Nariño Sweet Symphony: a deep sweetness, chocolatey undertones, a subtle note of almond and a creamy body.
• Tropical Dulce Dream: coconut and caramel as tasting notes, over a substantial body.
• Caldas Serenity Now: clean and sweet, with herbal undertones.

The Chinchiná Harmony Roast, our everyday coffee, is roasted for balance, so that its bright acidity and its sweetness sit together.

Tasting the difference

Brew Caldas Geisha Harmony and Nariño Sweet Symphony the same way, side by side, with the pour-over recipe in our brewing guide. The lighter cup will feel brighter and more transparent; the medium one rounder and sweeter. Both are washed coffees, but they differ in variety and origin too, so roast is one difference among several, not the only one.

For more on what else shapes a cup, read washed or natural and what single-origin means.