What is Channelling in Coffee Brewing?

In the world of espresso brewing, precision and mastery are key ingredients for crafting exceptional cups of coffee. As baristas, we constantly seek the holy grail of coffee extraction, striving to deliver that perfect, aromatic cup to our discerning customers. In our quest for excellence, we often encounter a daunting adversary known as channelling. But is it as catastrophic as it seems? Does channelling truly spell doom for your coffee? In this post, we delve into the intriguing world of channelling in coffee extraction to separate fact from fiction. So, let’s shed light on this topic, unravelling the mysteries behind channelling and exploring its nuances. Get ready to challenge conventional wisdom and discover the truth about channelling in the art of coffee extraction.

What is Channelling by the way?

In the context of espresso extraction, “channelling” refers to the uneven or inconsistent flow of water through the coffee grounds during the brewing process. When water doesn’t distribute evenly and instead finds a path of least resistance, it can create channels or gaps in the coffee bed. As a result, some areas of the coffee bed are over-extracted while others are under-extracted, leading to an imbalanced and potentially undesirable flavour profile in the final cup.

Is it always bad?

While channelling in espresso extraction is generally considered undesirable, it’s not always entirely bad. In certain espresso recipes or techniques, intentionally creating controlled channels can be used as a tool for manipulating the flavour profile. By adjusting the grind size, distribution, or tamping technique to encourage specific channels, baristas can highlight certain flavour notes or achieve unique brewing outcomes.

However, in most cases, unintentional channelling during regular coffee brewing is considered a negative occurrence. It leads to uneven extraction, resulting in a cup that may have over-extracted and bitter flavours in some areas, while other parts are under-extracted and lacking in flavour. Achieving a balanced and well-extracted cup typically requires minimising or eliminating channelling to ensure an even flow of water through the coffee bed.

What may occur Channelling? and How to Prevent

Channelling can occur due to various factors, including improper coffee grinding size, uneven coffee distribution or tamping inconsistencies.

Grind consistency: Ensure that the coffee grounds are uniformly sized to promote even extraction. Considering the quality of a grinder may solve this problem.

Coffee distribution: Distribute the coffee grounds evenly in the portafilter to make the equal density within the basket and hence to encourage a uniform flow of water. Manufacturers have developed various types of distribution tool to get better outcome, and these include the levelling tool, the needle distribution tool and etc.

Tamping technique: Apply consistent pressure and tamp parallel to create a level and compact coffee bed. The automatic tamping machine such as Puqpress is popular in the industry. [Click here to read ‘Learn More About Tamping in Detail’]

Conclusion

Channelling may be a formidable adversary in the world of coffee extraction, but armed with knowledge and the right techniques, baristas can conquer it. By understanding the causes of channelling, implementing preventive measures, and fine-tuning brewing variables, you can elevate your coffee craft to new heights. Embrace the challenge, refine your skills, and embark on a journey to master the art of coffee extraction, delivering exceptional cups of coffee that showcase your expertise and passion as a barista.