Roasting Process

What is the roasting process?

Roasted coffee Café Santa Helena

Before roasting the coffee beans, they have a green color and have a grassy aroma. They do not smell like coffee at all. When we roast coffee, different aroma compounds are developed. These compounds make the flavor of the coffee. With the roast process we can affect these aroma compounds and determine the flavor of the coffee.

“Roasting means transforming the properties of green beans to brown which is the drinkable coffee”

As the coffee absorbs heat, the color shifts to yellow and then to increasingly darker shades of brown. During the later stages of roasting, oils appear on the surface of the bean. The roast will continue to darken until it is removed from the heat source.

Roasting Stage:

1- Drying Stage – before roasting starts, the coffee beans have to dry for about 4-6 minutes and collect energy. In the end of the drying the temperature is 160°c.

2- Browning Stage – after 7-10 minutes the beans starts turning brown and a spicy smell develops and aroma compounds starts. Due to the gases (carbon dioxide and monoxide) forming in the beans, their increase significantly in volume.

3- Roasting Stage – after about 12-15 minutes the pressure in the beans is so great, and the reaction becomes exothermic. In this moment the coffee cracks (first crack). The cracks means that the coffee explode and the aroma compounds are developing. The fruit acids are broken down, sugars are caramelized and the cell structure is more weaken. The roast time is very important to reach the desirable flavor. The temperature hits 195°c.

During this stage the coffee’s colour changes from light brown to medium or dark brown.

When the roasting process is ready, the coffee falls from the roasting drum into the cooling sieve, and cool with cold air and an agitator.

Our coffee process is through slow artisan roasting, which means that organic acids have more time to break down and the coffee becomes less acidic. It is ideal to make a good espresso.

Roast degrees:

Are measured by color and tasting.

Green Coffee

Roasting process green coffee


Light roasts are more acidic with fruit flavors. They have a light brown color.

Roasting process light roast

Medium Roasts are a medium brown color, with a slightly heavier body than light roasts. They have more caffeine than dark roasts and a balanced flavor, aroma and acidity.

Roasting process medium roast

Dark roasts are more bitter, roasty and burnt flavors with less acidity.

Roasting process dark roast

Specialty Coffees and Single Origins would have a medium to dark roast.

“We roast the coffee slowly by hand in a wood roaster to preserve the delicates notes of fruits, honey, chocolate, caramel and hints of walnuts”.

What’s the difference between roasting for filter or espresso?

Filter Extraction – is done by gravity and its process is quite gentle. The coffee is very aromatic and more acidic. Typically the roast is medium.

Espresso – is extracted by pressure in a coffee machine. The roast is dark with low acidity and big body.

Roasting coffee for espresso  might not be as good when brewed as filter coffee and vice versa.

Filter, Moka or Espresso the important thing is to have a high quality coffee!

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