MIÓ, Chápela Yeast Fermentation Natural

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.

For this yeast fermentation process, the cherries are fermented in closed tanks for 72 hours using Saccharomyces cerevisiae as a starter yeast, with glucose and/or fructose added as fermentation substrates. This process creates a complex cup profile featuring sweet notes, syrupy mouthfeel, and mild acidity.

Mió is a forward-thinking, technology-driven coffee farm spanning 1,589 hectares. A third of the land houses coffee processing and milling facilities, alongside pasture areas and Eucalyptus plantations where thriving bee colonies make their home. The remaining land is split evenly between coffee trees and a native forest reserve, helping preserve the area's natural ecosystem. The estate's abundant spring water supplies many neighbouring properties, making water quality and flow management one of Mió's core responsibilities.

Through state-of-the-art facilities, Mió maintains exceptional traceability of their entire annual crop. Using satellite imagery, they monitor every stage of production—from cherry harvesting locations to truck movements and processing details. This advanced technology not only provides precise tracking but also improves farmworkers' quality of life, ensures bountiful harvests, and maintains the highest processing standards.

Mundo Novo is a coffee variety resulting from a natural cross between Bourbon and Typica, discovered in Mineiros do Tietê, São Paulo, Brazil. It's known for its productivity and good cup quality, but it's susceptible to major diseases. Mundo Novo has commercial importance in Brazil and other South American countries, including Peru. Costa Rica introduced it in 1952, but farmers didn't widely adopt it due to its very tall stature. This variety can also be found in Malawi, Africa. While vigorous and productive for a traditional American variety, Mundo Novo matures late.

The Catucaí variety was developed by researchers at the former Brazilian Coffee Institute (IBC). This cross between Catuaí and Icatu was first selected in 1988 from a population of the red Icatu cultivar. After generations of breeding and selection in Minas Gerais and Espírito Santo, the program produced cultivars with both red and yellow fruits. The plants are characterized by their low height, high productivity, early maturation, and disease resistance.

The dry/natural process is the oldest and simplest method of preparing green coffee. Well-suited to environments with limited water access and hot climates, this process typically uses no water and requires no specialized equipment.

After harvesting, coffee cherries are dried until they reach about 20% moisture content. They're then usually rested for a few weeks in bags before being sent to a mill for hulling and export preparation.

The cherries can be dried on large patios or raised African beds—large trays with a mesh base that allow increased airflow for even drying. Best practices include keeping the drying coffee in shade during the hottest parts of the day and avoiding re-wetting by rain or condensation. Regular turning and good ventilation are also crucial to prevent mould formation.

To avoid defective seeds and sour fermentation off-flavours, it's best to sort the harvested cherries during the initial drying stage when under-ripe, over-ripe, and damaged cherries are easily spotted. After just a couple of days, the cherries turn a dark red-brown colour before becoming black, making it impossible to visually identify problem cherries.

Coffee begins fermenting from the moment it's picked and continues while there's enough moisture and high temperatures—conditions that favour microbial growth. This uncontrolled fermentation leads to the development of wild, fruity flavours and an increased perception of sweetness and body.