Paahto

Paahto is the process of heating coffee beans or other edible seeds and grains to develop aroma, flavor, and color. In Finnish, the term is central to coffee production and is carried out in a roastery (paahtimo). While coffee is the most common reference, paahto can also describe toasting of grains, nuts, or cocoa in culinary contexts.

During roasting, beans are heated in drum or hot-air roasters. The process typically includes drying, browning, and development phases as moisture is driven off and sugars and amino acids participate in Maillard reactions. Roasters adjust heat, airflow, and roast duration to achieve the desired flavor profile. Cues such as the first crack and, for darker roasts, the second crack guide decision points. Temperature and development time influence acidity, body, sweetness, and aroma.

Roast levels are commonly categorized as light, medium, and dark, with subcategories in between. Light roasts preserve origin characteristics and higher acidity; dark roasts emphasize roasted flavors, bitterness, and a fuller body. Caffeine content is not strictly tied to roast level; brewing with the same amount of coffee by weight can yield similar caffeine levels across different roasts, though taste and perceived strength will differ.

In practice, paahto shapes how coffee flavors are perceived and marketed. Roasters tailor profiles to highlight bean origin, processing methods, or desired sensory characteristics. The term reflects both a technical process and a key step in delivering the flavor and aroma of coffee to consumers.