Zest Specialty Coffee on how each step in the chain contributes to flavour

Zest Specialty Coffee’s Tim Fullerton provides a barista’s outlook in what variables impact coffee flavour and why each step in the chain contributes to the end result.
Zest Specialty Coffee

In my early days as a barista, supply chain blame always came to the fore whenever there was a complaint from a customer about the coffee. An unskilled barista would blame the roaster, the roaster would blame the green beans.

Having trust in the production chain, however, is crucial. The end flavour of a coffee relies on the strong journey of skill and transparency throughout the chain. Each link has to trust every link before them. Trust that the green beans were bought with good faith on quality, trust that the roaster has the right profiles to get the best out of the coffee, and trust that the barista has the skills and equipment to extract the most flavour.

As an initial consumer, I had no idea about the origin of my coffee and how its handling could result in “good” or “bad” flavour coffee. 

Moving into a professional barista role opened me up to coffee’s many variables and the impact these have on flavour, such as grind size, dose, yield, and extraction time.

Mastering technique was one thing, keeping the dose consistent was another. I will never forget the words drummed into me from the start: “Finer equals slower, coarser equals faster. Look for the drop, shut off the shot when it looks right. Taste. Adjust. Taste it again. Every thing depended on that flavour and that flavour depended on everything being done just right.

In those early years, scales were not a part of the setup, neither was timing shots. A lot of the skill came down to taste and feel, and knowing the variables. Learning to taste the espresso and make adjustments was key. Repeating and controlling the variables was what made the coffee taste the best it could – as often as possible. But still, not all coffee flavour was the same.

As my extraction skills improved, my curiosity about flavour grew. I would taste different origins, blends and micro-lots each day, and wonder how each bean inherited its own distinct flavour.

Researching coffee farming, growing, and processing was the next step in my flavour journey. I am still exploring this today, and I know my efforts will be rewarded with more questions and more variables. 

For now, being familiar with the many coffee varietals, the main growing regions, and the varying processing methods has given me a new path to discover. Pinning them down has always been the aim of the game, and having as much control over these as possible is what gets you closer to consistently good flavour. 

The new age barista has a raft of tools at their disposal, such as timed grinders, scale, shot timers, funnels and distribution tools. Dialling in the shot is much easier and repeating these numbers ensures consistency.

A sour, hollow, and astringent assault on the palate comes from poor technique and neglecting these variables.

I now have the opportunity to learn small batch specialty roasting on a vintage Probat UG15 at Zest’s Marrickville roastery. 

As a roaster, I now shoulder responsibility in a different way. Endless principles, theories and techniques combine with a whole new world of variables. Moving into a roasting role has put me back to where I was all those years ago starting behind the espresso machine. 

Just as I was learning to recognise extraction time, I am now understanding the nuances between growing regions, metres above sea level, density, screen size, washed, honey and natural processing, and anaerobic fermentation.

The roasting process is a new journey of discovery. I do lots of assessments, endless cuppings, and I’ve learned how to manipulate development time, and understand the chemical reactions responsible for drawing out flavours.

I’m on a very different path now to the one I was as a barista and as a consumer, but one thing remains the same. I’m still just an explorer digging through variables to find the same treasure, the best cup of coffee.