The Myth of Universal Roast Profiles: Insights from Fluid Bed Roasting
Introduction
Hello coffee lover, welcome back to another edition of Coffee Truth. I am your host, Pak Kopi. In this article, we will explore roast profiles and the specific dynamics of fluid bed roasting. My goal is to share a recent experience that demonstrates what I believe is the ineffectiveness of rigid roast profiles, particularly when applied to fluid bed roasting.
Fluid Bed vs. Drum Roasting
Fluid bed roasting is a distinct process that utilizes electricity and hot air, as opposed to drum roasting, which typically relies on propane as its heat source. Consequently, fluid bed roasting is often considered a much cleaner and arguably superior process. However, the transition to digital control systems and fixed “profiles” introduces significant complications that may not be immediately apparent to the average roaster.
The Challenge of Global Voltage Variability
To understand why universal roast profiles fail, we must look at the testing conducted in China during the Kickstarter campaign for our power roaster machine. While the internal parts, specifically the heating and fan assemblies, were manufactured there, the machine had to be tested against various global electrical standards.
There are three main voltages worldwide: 230 volts, 120 volts, and 100 volts. To satisfy customers globally, we had to test the machine at specific wattages and voltages to achieve a consistent outcome: roasting 120 grams of coffee in six minutes. Crucially, users must have the ability to control the roast from light to dark; therefore, the roast cannot be too fast or too slow.
The Singapore vs. Indonesia Experiment
After completing our tests in China, we deployed two machines to different regions to monitor their performance:
- One machine was sent to Singapore.
- One machine was taken to Bali, Indonesia.
Unexpected Results
Upon deployment, we encountered vastly different results despite using the same machine settings:
- Singapore: The machine was roasting “way too fast,” completing the batch in approximately four minutes.
- Indonesia: The opposite occurred; my roast took about seven minutes, significantly longer than the target.
The Conclusion on Electricity Sources
We investigated every possible variable before arriving at the only logical conclusion: the electricity source itself differs between countries.
- Singapore: Delivers power in a way that causes excessively fast roasting at 230 volts.
- Indonesia: Experiences significant fluctuations (“up and down”) in the grid. To maintain a consistent 220-volt source, I utilize a voltage regulator.
This inconsistency extends beyond Asia. It is highly probable that the electricity delivered in the U.S., Canada, and Europe will also vary slightly from one another. Therefore, attempting to copy a roast profile from one country to another using computer-controlled parameters is, in my opinion, impossible.
Design Philosophy: Simplicity Over Complexity
Because the electrical source in every country is inherently different, our Power Roaster does not feature complex extra controls. It utilizes a simple on/off switch. This design forces the user to determine when to stop the roast based on their specific local conditions.
To address the issue of roasting too fast in regions like Singapore, we are exploring two potential solutions:
- Manufacturing a special machine version with reduced wattage for specific regional needs.
- Developing a built-in voltage regulator that allows users to dial down the voltage (e.g., to 75%) to lengthen the roast time.
Our ultimate goal remains the same: ensuring the user has enough time to stop the roast and achieve the desired profile, ranging from light to dark.
The Fickleness of Coffee
This experience highlighted the fickleness of coffee. Even when using the same equipment, the same beans, and the same theoretical roast, the result changes every time. This is due to ambient factors such as temperature and barometric pressure, which influence the roasting process.
It seems that coffee is “new” every single time, yielding slightly different results. While many enthusiasts focus on swapping computer programs and adhering strictly to roast profiles, my experience suggests these methods often fail in practice. There are likely parameters we have not yet fully figured out, such as the exact amount of electricity flowing through a wall socket and its consistency from day to day.
Conclusion
We don’t put out extra controls on our machines because the electrical reality of each country is unique. The user must be empowered to manage the roast based on their local environment.
I would love to hear from the community: Have you tried duplicating roast profiles across different countries or voltage settings? Have you experienced success or failure? Your stories and experiences are vital to understanding the full scope of this challenge.
Thank you for watching this video and for your continued support. We will see you again next time.
