What is thermoshock coffee?
Everything you need to know about the thermoshock processing/fermentation technique & why it makes coffee taste so good!
What is thermoshock coffee?
“thermoshock is a type of anaerobic fermentation coffee process (read: oxygen is removed from the coffee’s environment) that greatly enhances a coffee's level of sweetness.”
Gone are the days when coffee was simply referred to as undergoing a ‘washed’, ‘natural’ or ‘honey’ process. Now more than ever, producers are coming up with increasingly progressive ways to alter the flavours that end up in your coffee cup.
We’ve touched on carbonic maceration in the past, and now we’re thrilled to provide you with a detailed breakdown on exactly what thermoshock coffee is!
WHAT IS THERMOSHOCK COFFEE?
At its most bare bones definition, thermoshock is a type of anaerobic fermentation process (read: oxygen is removed from the environment for a period of time) that greatly enhances a coffee's level of sweetness.
In saying that, such a basic definition belies what is quite a complex and innovative process first pioneered by Colombian producer Wilton Benitez!
The producer behind some of our quickest-selling single origins (i.e. the two Colombia, Finca El Paraiso cans from November 2023), Benitez put his background in chemical engineering to full use when creating this processing method.
While terroir—variety, altitude, soil, local climate, etc.—determine a coffee’s inherent flavour, it’s the changeable variables in the fermentation process—think microbes, introduced cultures/yeasts, and temperature—that helps coffee acquire its final flavour profile.
Keeping the latter in mind, Benitez's first trials of the thermoshock method were really all about playing with temperature in particular.
During his first trials, Benitez fermented whole cherries without oxygen (anaerobic fermentation) often twice over before washing the pulped beans in warm water, and then cold water directly afterwards. This is where the process gets its name from!
By washing the beans in warm then cold water (playing with thermal temperature), Benitez is shocking the beans into sealing in acquired flavours developed during the double anaerobic fermentation process.
Benitez has refined the method even further since those first rounds of experimentation, and one of the newer thermoshock recipes is listed in full below.
A STEP-BY-STEP SCIENTIFIC BREAKDOWN OF THERMOSHOCK PROCESSING
- The ripest coffee cherries are selected according to a strict criteria, characterised, and sterilised.
- As whole cherries, the batch undergoes its first round of anaerobic fermentation. During this period, the producer will also introduce a special yeast microorganism that positively influences each cherries' flavour compounds.
- After the first fermentation, coffee is pulped and subjected to its second fermentation. The sugars from the mucilage (pectin layers) of the coffee cherry are given further time to absorb into the coffee bean.
- Now comes the ‘bean sealing’ phase. Post-fermentation, this is the step where thermoshocking actually occurs. Benitez takes the beans and washes them in hot water, then cold water.
- Once washed, the beans are laid out in a controlled environment (greenhouse or drying beds) to dry until the beans achieve the desired moisture content.
WHY WE LOVE THERMOSHOCK COFFEE
As mentioned earlier, using the thermoshock method can greatly enhance the coffee’s sweetness and overall organoleptic properties. Alongside sweetness, the bean sealing phase of the thermoshock method also traps delicious aroma compounds into the coffee, which only become released upon brewing.
Moreover, because thermoshock coffees go through more processing than most, a light touch is preferred at the latter end of the bean’s crop-to-cup journey! Specifically, this is why we light roast all of our thermoshock coffees and recommend brewing as a filter.
If you already have a thermoshock coffee on standby, we have all your filter-brewing needs covered with our Origami collection. Alternatively, follow us on Instagram—then when we drop our next thermoshock coffee, you’ll be among the first to know!
