Table of Contents
- What is Compound Chilling?
- Compound Chilling Introduced in WBC
- How to Brew Compound Chilling Espresso
- Science Behind The Technique
- Baristas’ Reviews for Reference
What is Compound Chilling?
Compound Chilling in espresso extraction refers to rapidly cooling down the freshly brewed espresso. This technique typically involves a frozen metal ball to swiftly lower the temperature of the coffee, enabling the espresso to retain approximately 10% more volatile compounds. Because it is also a process of cooling the espresso extract, the term sometimes is called ‘Extract Chilling’ as well.
Compound Chilling Introduced in WBC
This concept gained prominence during the 2021 World Barista Championship (WBC) when Hugh Kelly, a three-time Australian Barista Champion, incorporated it into his espresso routine. He involved a technique of extracting the coffee over a frozen metal cube. It’s worth noting that this concept had been explored earlier. In the 2013 WBC Final, Matt Perger utilised frozen cups to extract shots of espresso. However, this concept wasn’t extensively introduced to the coffee industry at that time because placing a cold cup couldn’t explain the idea enough. It can be observed that Hugh Kelly played a role in revitalising and popularising the idea of ‘compound chilling’ by the use of the cubes.
How to Brew Compound Chilling Espresso
Ingredients and Equipment
- Espresso machine
- Stainless-steel or metal ball
- Strainer or holder
- Cup
Step by step instructions
- Place the stainless-stell or metal ball in the freezer before coffee preparation. When the ball is cold enough, it’s ready to use.
- Prepare a strainer on top of a cup that can hold the frozen metal ball above the cup.
- Make sure that espresso would drop onto the ball directly so that the freshly brewed coffee gets chilled immediately.
- Start extracting espresso. Below is the example of the preparation.
Science Behind The Technique
Volatile compounds in espresso possess greater vapour pressures compared to non-volatile compounds at room temperature. Consequently, as temperature rises, volatile compounds absorb more kinetic energy, leading to faster evaporation. Through the rapidly cooling of espresso, a more of the volatile compounds responsible for the aromatic flavours are conserved within the liquid. Compound chilling espresso has the capacity to safeguard an average of up to 10% more volatile compounds than classic espresso extraction, resulting in the preservation of a greater portion of delicate flavours.
Baristas’ Reviews for Reference
In addition to the scientific evidence, many baristas have tried this technique and are responding positively. You may hear about their experiences here (Reddit).
Conclusion
In the culmination of our exploration into compound chilling, we uncover a tantalising gateway to heightened coffee experiences. With each chilled extraction, we embrace a symphony of flavours, preserving the delicate notes and painting a vibrant canvas of taste. As the technique steps into the spotlight, we witness the evolving artistry and science of coffee, paving the way for richer, more nuanced sips.
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