Before roasting coffee, it is extremely important to remove any imperfections from the green beans to ensure a good roasting result. Each different defect detected in green coffee affects the roasting, resulting in bad flavors from the coffee in the cup
Effects of green coffee on roasting
The type of green coffee tree, its type, the quality of that year’s harvest, the way it is picked and husked, transportation, storage conditions, defects and humidity affect the roasting quality of the coffee. Different green coffees have different roasting methods. Different coffees require different roasting times, roasting temperatures, roasting temperatures and roasting recipes. A good roaster pays attention to all these aspects. He records the characteristics of the green coffee he roasted for the first time from a particular origin, all the reactions during roasting, the roasting conditions, the characteristics and aromas of the resulting roasted coffee. In the future, when roasting green coffee from the same origin, he applies the same roasting recipe. If the resulting roasted coffee has different characteristics and aroma, there is a problem with the origin information or production conditions of the green coffee. In this case, a new change in the roasting recipe is necessary to obtain the desired roasted coffee and its characteristics. In short, when buying new green coffee, the product must be tested and checked for defects
Defect in green coffee
One of the most important factors affecting the quality of coffee is the defects in green coffee, which are classified into five different groups and defined by the following characteristics
- Defects related to foreign body,
- Defects related to substances from the fruit that are not present in the green coffee bean,
- Errors related to irregular green coffee grain,
- Visual disturbances in the green coffee grain,
- Tasting and flavor defects
Green coffee defects have a major impact on mass loss and sensory losses. Each defect in green coffee beans is assigned a value depending on the degree to which it affects the properties of the roasted coffee. Some international coffee standards apply to defects
- Green Coffee Classification, used by the New York Board of Trade (NYBOT) and Brazil
- ISO 10470 – 1993 Assessment
- ISO 10470 – 2004 Assessment
- TCVN 4193 (Vietnam)
- Indonesia Standard
- LIFFE Gradings System