Coffee beans roasting

The roasting process transforms green beans into aromatic coffee, defining flavor and body. Discover stages and characteristics.

About this subject

Coffee roasting is an essential step between harvest and brewing. Green beans, initially odorless, are subjected to temperatures between 180°C and 240°C, triggering complex chemical reactions. The Maillard reaction and sugar caramelization develop over 800 aromatic compounds. The process lasts 8 to 20 minutes, depending on the desired profile.

During roasting, beans undergo two audible cracks: the first at around 196°C, marking light to medium roasts; the second near 224°C, indicating dark roasts. Mass loss reaches 15-20% due to water evaporation and cellulose breakdown. Each roast level highlights different attributes: light roasts preserve acidity and floral notes, while dark roasts bring bitterness and full body.

Bean origin also influences the ideal roast profile. High-altitude arabica coffees from Colombia or Ethiopia are often lightly roasted to enhance complexity. Robusta, common in Brazil and Vietnam, frequently receives dark roasts to mask bitterness and boost crema. Roasting is an art balancing science and intuition.

Modern methods use rotating drums or fluidized beds with precise temperature and time control. The 2026 trend points toward artisanal roasts and personalized profiles, valuing bean traceability. Roasting also releases carbon dioxide, which must be degassed before brewing. Understanding these details helps choose the perfect coffee for any taste.

Frequently Asked Questions

What is the difference between light and dark roast?

Light roast preserves acidity and floral flavors, while dark roast develops bitter and bold notes with less acidity.

How long does coffee roasting take?

It takes 8 to 20 minutes, depending on temperature and method. Lighter roasts are quicker.

Can you roast coffee at home?

Yes, using pans, ovens, or dedicated machines. It requires attention to uniformity and temperature control.