Thursday, 23 April 2015 21:00

Citric Acid

Like many living organisms, citric acid plays an important role as a key intermediate compound in the plant's metabolic cycle. In green coffee citric acid makes up a significant portion of coffee's total acid content and ultimately in the development of perceived acidity. 

During roasting, citric acid reaches a maximum at light to medium roasts then quickly diminishes as roasting levels progress. A typical medium roast will lose about 50% of its initial citric acid concentration and with progressive destruction in latter stages of roasting progresses. 

From a taste perspective, citric exhibits strong sour characteristics similar to what we would taste in unripe fruits. Although pure citric acid is commonly used as a food additive to impart sour/tart notes, excessive citric acid is a sign of bad processing.  

Since a high concentration of citric acid is found in unripe (green) cherries, it is important for producers to only pick the ripest beans, especially for those bean destined to become specialty coffee. 
 

Unripe and ripe coffee cherries
Unripe/Ripe Coffee Cherries 

However, as maturation continues citric acid levels continue to decrease with a parallel increase in sugar production. Generally, Kenyan coffee tend to have lower levels of citric acid than those of Central America, suggesting a less advanced form of plant metabolism.

Read 19624 times Last modified on Saturday, 19 March 2016 11:16
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