Thermal shock
After fermenting, the coffee is rinsed in hot water and then cold, a Colombian technique for a vivid, aromatic cup.
Thermal shock is a washing step, not a fermentation of its own. After the coffee has fermented, often in sealed tanks and sometimes with added yeasts, it's rinsed in hot water and then quickly in cold. Producers say the sudden change in temperature helps the seed absorb the aromas built up during fermentation and then locks them in.
The technique is associated with Colombian producers, especially Diego Bermúdez of Finca El Paraíso in Cauca, who helped make it famous in the late 2010s. Thermal-shocked coffees tend to be intensely aromatic and fruity, often tropical or floral, and they're usually layered with other techniques, so they're rarely cheap.
- Step
- A hot-water rinse, then a cold one, after fermenting
- Usually with
- Anaerobic fermentation, added yeasts
- Associated with
- Colombia; Diego Bermúdez, Finca El Paraíso
- Tastes
- Intensely aromatic, tropical and floral
- Signature notes
- peach, mango, jasmine
- Origins
- Colombia (83), India (1), Indonesia (1)
- Varieties
- Gesha (19), Castillo (13), Caturra (10), Ombligon (7), Pink Bourbon (6), Pacamara (4), Sidra (4), Chiroso (3)
- Flavors
- Stone fruit (39), Floral (38), Caramel & sugar (37), Tropical (33), Red fruit (32), Citrus (31), Berry (28), Chocolate (15)
On the bag
- Advanced washed, advanced natural
- House names some producers use for their own sequences, often anaerobic fermentation with added yeast and a thermal-shock rinse.
Roasters that carry it most
- Moxie (8)
- Perc (19)
- Black & White (33)