Thermal shock
Fermentation is stopped by swinging the temperature hard rather than by washing or waiting. The shift is the technique.
- Family
- Anaerobic
- Processing character
- Transformative
Thermal shock uses temperature as the control. After a sealed fermentation, the coffee is run through a rapid swing between hot and cold water instead of being washed off at ambient temperature and left to finish.
The swing does two things. It arrests microbial activity at the moment the producer chooses rather than wherever the tank happens to land, and the rapid change appears to lock in volatile aromatic compounds built during the ferment that would otherwise be lost through the wash and the dry.
It came out of the experimental Colombian scene and it needs real equipment. Heating and chilling water to a target, holding it there, and moving coffee through it on a schedule is not something a farm improvises. Producers running it track temperature and time through the whole sequence.
It sits at the top of our processing character scale, and not because anything was added. Nothing is. It's there because what you taste is dominated by what the ferment and the shock did, which is the only thing that scale measures.
The swing does two things. It arrests microbial activity at the moment the producer chooses rather than wherever the tank happens to land, and the rapid change appears to lock in volatile aromatic compounds built during the ferment that would otherwise be lost through the wash and the dry.
It came out of the experimental Colombian scene and it needs real equipment. Heating and chilling water to a target, holding it there, and moving coffee through it on a schedule is not something a farm improvises. Producers running it track temperature and time through the whole sequence.
It sits at the top of our processing character scale, and not because anything was added. Nothing is. It's there because what you taste is dominated by what the ferment and the shock did, which is the only thing that scale measures.
This is the starting presumption for the processing character scale. An individual coffee can sit higher or lower when the cup says so.
