Experimental coffee processing continues to reshape the flavour landscape of specialty coffee — and one technique we’ve been sourcing and roasting for several years now is thermal shock coffee processing. Among UK specialty coffee roasters, this method has gained attention for producing intensely aromatic, fruit-forward coffees with remarkable clarity and structure.

But thermal shock isn’t just a trend. Behind the name is a carefully controlled fermentation approach rooted in temperature manipulation and microbial science. When executed well, it can unlock vibrant sweetness, layered acidity, and striking flavour precision — without sacrificing balance.

In this guide, we break down exactly how thermal shock coffee processing works, the science behind it, and what it means for your cup when you see it on one of our coffees.

A deep, science-driven exploration of how fruit juice transforms coffee during co-fermentation. Dive into the microbial ecology behind the process, unpacking how added sugars reshape fermentation dynamics, influence organic acid development, shift pH balance, and introduce key nitrogen sources and micronutrients. Discover how fruit juice fuels enhanced metabolic pathways — driving intense ester formation, complex amino acid conversions, and nuanced acid metabolism and buffering. Follow each stage of fermentation to understand what’s happening at a biochemical level, and learn how these changes ultimately shape flavour, structure, and the final cup profile in this bold, experimental processing style.

A little deep dive into a relatively new style of modern processing within coffee, Fruit co-fermentation. Focusing in particular in this post on Peach as an example of what fruit can provide during co-fermentation to effect the flavour of coffee.