To make the most of the full harvest, the folks at Monteblanco measure the degrees Brix of each lot of cherries as they come off the trees to determine the sugar content. Based on the amount of sugar in the coffee cherries, Monteblanco uses a protocol — established through years of testing, trial, and error — to designate the appropriate processing for each lot.
28 - 32 degrees Brix — Double Fermentation
Cherries ferment for 36 hours in a tank and are then depulped and left to ferment an additional 44 hours before being washed and transferred to shaded beds to dry for 28 days. Double Fermentation increases the time the bean is in contact with the sugars from the cherry, ideal for coffees with a slightly higher Brix content than those destined for Natural processing.
The goal of Double Fermentation is to bring out the sweetness and complexity of the coffee. As long as the cherries do not exceed 28 degrees Brix to begin with, the first fermentation phase of the Double Fermentation process can increase Brix readings by as much as 4 degrees Brix, provided that the pH does not drop below 5 and disrupt the equilibrium between body and acidity.