Coffee cherries that begin drying while still attached to the tree are considered overripe and typically make up only a small percentage of the harvest. This season has been particularly challenging for farmers in Minas Gerais, as drought conditions have accelerated cherry ripening. What would normally be a two-month harvest has been compressed into a dramatically shorter timeframe. This surge in volume has created significant logistical challenges at the processing station, and the abundance of overripe cherries could have been a serious quality issue—if not for some innovative thinking and experimental processing, spearheaded by Professor Lucas Louzada.
In the Controlled Germination process, the cherries undergo multiple stages: first, they ferment in an anaerobic environment inside the bioreactor for 36h at 38°C, then experience oxygenation and steeping in water for 12h at 21°C. After removing the oxygen and water, they return to an anaerobic environment for another 36h. This cycle of oxygenation and steeping repeats 3 times over 144h. The process activates enzymes that convert starch into sugars like maltose and maltotriose. It also promotes the growth of bacteria from the Enterobacteriaceae genus, whose metabolism creates coffee with juicy, fruity, and floral flavour profiles.