THE PROCESS IN MOTION

What does thermal shock really show?

Start the scene or choose a stage. The animation simplifies the mechanism; what follows gives the details and the available references.

▶ Play the process01Whole cherry, then second fermentation02Homogenizing in warm water03Stopping with cold04Washing with thermal shock

Whole cherry, then second fermentation

At Finca El Paraíso, in Cauca, the whole cherry ferments anaerobically for 48 to 72 hours, one source specifying 60. A second fermentation follows pulping, from 24 to 96 hours. The documentation is almost entirely journalistic: it is a reported description, not a measurement.

Read the stages without animation

1. Whole cherry, then second fermentationAt Finca El Paraíso, in Cauca, the whole cherry ferments anaerobically for 48 to 72 hours, one source specifying 60. A second fermentation follows pulping, from 24 to 96 hours. The documentation is almost entirely journalistic: it is a reported description, not a measurement.
2. Homogenizing in warm waterThe mass moves to a larger tank, with water at 35-40 °C, to be homogenized for 60 hours.
3. Stopping with coldThe fermentation is then stopped by cold, for 8 hours.
4. Washing with thermal shockThen comes the washing: hot water around 40 °C, immediately followed by cold water around 10 °C. The explanation given is a dilation of the pores under the heat, then a sudden contraction that would fix the aromas in the kernel, the heart of the bean: a producer's explanation, not demonstrated, and with figures that vary from one source to another.

To remember: The sequence and its figures come mostly from reports and from producers, not from a published reproducible trial.

In history: Another farm in Cauca, Granja Paraíso 92, sterilizes its cherries, dips them for 30 seconds at 70 °C and ferments for 96 hours in a bioreactor; nothing is published.

Read the full article and its sources ↓

Two Colombian farms have pushed control further than anyone. Their documentation, however, is almost entirely journalistic: what follows is a reported description, not a measurement.

Diego Bermúdez, Finca El Paraíso, Cauca. Whole cherry in anaerobic conditions for 48 to 72 hours, one source specifying 60. Second fermentation after pulping, from 24 to 96 hours. Transfer to a wider tank with water at 35-40 °C to homogenize the mass for 60 hours. Stop by cold, 8 hours. Then the washing as thermal shock: hot water at around 40 °C, immediately followed by cold water at around 10 °C.

The explanation given is a dilation of the pores under heat, then a sudden contraction in the cold that would fix the aromatic compounds in the kernel. It is a producer's explanation, not demonstrated, and the figures vary from one source to another.

Wilton Benítez, Granja Paraíso 92. Sterilization with ozonated water and ultraviolet light, immersion at 70 °C for 30 seconds, pulping, then 96 hours in an anaerobic bioreactor inoculated with Saccharomyces pastorianus. The pH, Brix, conductivity and temperature are monitored continuously. Mechanical drying at 38 °C for 46 hours. No publication.

In ten years, specialty coffee has equipped itself with a toolkit of directed fermentation. It has not equipped itself with the literature that goes with it.

Trade press and importers, medium to low level; LC ch. 17b