As the pursuit of the perfect cup of coffee continues to evolve, innovative techniques continue to emerge that seek to enhance each aspect of the brewing process. One method that has been gaining traction among coffee enthusiasts is the compound chilling, or extract chilling, of espresso. This nuanced approach goes beyond the traditional iced coffee or cold brew, offering a unique way to enjoy the rich flavors of espresso in a chilled format. In this article, we'll explore the concept of extract chilling, how it differs from other cold coffee preparations, and why it has become a compelling trend in the world of specialty coffee.
As part of his 2021 World Barista Championship (WBC) performance, Australian Barista Champion, Hugh Kelly, employed a unique technique by extracting espresso over a frozen metal block that sat directly below the portafilter. As the espresso extracted, it was rapidly chilled, preserving the intricate flavor compounds of the coffee that would normally be lost in the aroma of the coffee in the form of vapor, and enhancing its inherent sweetness. In essence, Hugh was trapping these flavors by tightening the overall structure of the espresso. By removing the heat element of the espresso extraction, Hugh was left with something that noticeably heightened the sweetness and overall balance of the shot. Hugh would go on to place third at the 2021 World Barista Championship, and alongside other WBC participants, would team up with researchers from the Zurich University of Applied Sciences (ZHAW) to continue testing how extract chilling works and how to gain the most from the practice.
Enter the Nucleus Paragon
Building off of the notable results found by Hugh Kelly, the Zurich University of Applied Sciences, and other baristas who had partnered with ZHAW, Nucleus set forth to create a product that would achieve the extract chilling of espresso, specifically with baristas and coffee enthusiasts in mind. The Paragon's revolutionary design incorporates innovative extract chilling technology to enhance the overall espresso experience. Developed through extensive research spanning several years, this tool has been scientifically proven to capture and release an impressive 40% more essential aroma volatile molecules compared to a regular brew without chilling. This ensures that no flavor is lost to the surroundings, providing an unparalleled sensory experience.
Brewing espresso over the Nucleus Paragon yields incredibly interesting results, with a dramatic increase in the sweetness, body, and overall balance of the espresso. The texture of an extract chilled shot is also drastically changed, becoming far more velvety with a long-lasting mouthfeel, and any coffee with even the slightest semblance of fruit flavors is greatly intensified. It becomes a different shot altogether, with Hugh saying of extract chilled espresso, “it was like the coffee had woken up.”
Cold coffee is nothing new, with cold brew taking the world by storm in the early 2000s due to its increased sweetness and decreased acidity. Flash brew pour-overs, first developed in Japan in the 1960s, have also steadily gained popularity with each passing year. Now, we may be in the era the popularization of extract chilling of espresso, and this can be seen in the use of the Nucleus Paragon being used by Morgan Eckroth, Jamie Patel, and Frank La at the United States Coffee Championship qualifying rounds, with all three advancing to the United States Barista Championship. Extract chilling is also being used in specialty cafes all over the world, so the results speak for themselves. While extract chilling may not be practical for every shot pulled in a high-volume cafe just yet, the Nucleus Paragon has certainly brought us a step closer to that becoming a reality. It’s safe to say that we may be on the cusp of a new, exciting coffee trend once again.