Better than the best: choosing between the L100 Ultra and L100 Plus
Curious about the difference between the L100 Plus and the new L100 Ultra? In this article, we break down the key upgrades and innovations—and share insights from coffee expert Christopher Feran on what the Ultra means for the future of sample roasting.
Since its launch in 2022, the ROEST L100 Plus quickly earned its reputation as the premier sample roaster on the market. Now, ROEST is raising the bar once again with the launch of the L100 Ultra, which begins shipping late July.
At first glance, the two roasters may look alike—but under the hood, the Ultra conceals a radically different core. So, if you're looking for the ultimate in sample roasting performance, which machine should you choose?
The ROEST family of sample roasters
All ROEST models share the same chassis and distinctive aesthetic, but they differ in sensor configurations and capabilities. Until the launch of the Ultra, all ROEST models—including the S100 and the L100 Plus—operated in a similar way. The key differences lie in the sensors available.
The updated S100 includes bean, air, and now inlet temperature sensors. The L100 Plus takes it a step further, adding exhaust and drum temperature sensors, first crack detection, and a suite of other features designed to boost consistency and streamline your workflow. Crucially, the fundamental roast style across these machines remains consistent.
The consistent performance and quality of these machines helped cement ROEST’s reputation for making the most efficient, precise, and consistent sample roasters available today. The new L100 Ultra builds on that heritage, but also introduces a completely new way of working.
A classic reimagined: L100 Ultra in Classic mode
In "Classic mode", the L100 Ultra can replicate the roast style of the L100 Plus, yielding similar exceptional results, but with some significant enhancements:
More Powerful CPU & Revamped Interface: The Ultra boasts a more advanced chip, powering a superior screen and a redesigned interface that make setup and control more intuitive.
Improved Airflow Path: Key points in the airflow path have been re-engineered to allow for more efficient heat transfer.
Redesigned Heating Element: The new element has a longer lifespan and allows for greater airflow through the system.
Reworked Temperature Probe Positions: Probes have been strategically repositioned to give more reliable readings across a wider range of batch sizes.
Drum Pressure Sensor: The Ultra adds a pressure sensor, offering superior control over airflow and easier calibration between different roaster setups.
The result? The Ultra delivers the same fantastic ROEST flavor you've come to expect, but is now easier to control, more efficient—and quite simply more fun to use. These features alone would represent a substantial upgrade over the L100 Plus. But the Ultra also introduces a ‘revolutionary’ new way of roasting: Counterflow mode.
ROESTing in a new direction: Introducing Counterflow mode
In classic mode (and in earlier ROEST machines), the drum rotates clockwise. The rotation of the paddles pushes the beans away from the hot air inlet, and then lifts them into the airflow. It's a convection-based system that mimics the feel of traditional drum roasters.
In Counterflow mode, the drum rotates in the opposite direction. The paddles drive beans directly into the airflow, meaning the air and beans move in opposite directions – hence, "counterflow". This counterflow movement is highly efficient for heat transfer.
Meanwhile, the bulk of the bean pile sits directly over the air inlet, forcing the air to pass through the beans before exiting. This ensures that the beans absorb heat from the incoming air much more effectively.
This highly efficient heat transfer opens up two exciting possibilities: you can either roast significantly faster, or you can achieve the same roast speed at much lower temperatures.
Ultra-high speed roasting
The efficiency of Counterflow mode, combined with the Ultra's improved airflow characteristics, allows for incredibly fast roasting. In fact, it's possible to bring a 100g batch to second crack in just 90 seconds!
The L100 Ultra lets you roast faster than ever before. This batch was ready in less than 4 minutes, and yet the profile only used about 60% of the maximum power available.
This capability allows you to replicate roasting styles from a wide array of machines, from the fastest industrial hot-air roasters to more traditional drum roaster style profiles.
It also means you can process samples with unprecedented speed. Since each batch can cool while the next is roasting, a counterflow profile could enable you to handle as many as 15+ batches per hour, vs 10+ batches with the L100 Plus.
Furthermore, because the drum doesn't get as hot during roasting, the cooldown time between batches is drastically reduced. Using the automated between-batch protocol to reset the machine's thermal energy, your workflow can become incredibly fast, efficient, and consistent.
Fast but gentle
Counterflow mode isn’t just built for speed. Its efficient heat transfer also lets you achieve more typical sample roast times at much lower temperatures—ideal for preserving delicate flavors in high-quality coffees. This gentle approach is perfect for coaxing out the subtle, nuanced flavors from more delicate beans, whether that's a washed Geisha or a wild 280-hour anaerobic processed coffee.
A typical sample roast on the L100 Plus takes 7–8 minutes. The Ultra can achieve this roast time while keeping inlet temperatures below 230 °C (445 °F)—an incredibly low and gentle approach for the coffee.
According to Scott Rao, this ability to roast at lower temperatures has “massively improved” his results, making his roasts “softer, less harsh, and easier to develop.”
‘Low and slow’ roasting on the L100 Ultra: In this roast, the inlet temperature never goes above 230 °C, while the drum temperature peaks at just 145 °C
Even at low temperatures, the roast can still be relatively fast. You can comfortably achieve a 5-minute roast while keeping the maximum inlet temperature around 250 °C (480 °F). So, you can forget about the "low and slow" approach for those hard-to-roast beans; with the Ultra, you can go low, and go fast.
Low and fast: this 100g batch reached first crack in less than 4 minutes, with the inlet temperature peaking at just 253 °C
This "fast but gentle" approach means the Ultra unlocks a whole new range of roast styles and flavors that simply aren't possible with conventional sample roasters. Faster roasts tend to be brighter and more soluble, while if you prefer the body and flavor of a more conventional roast style, you can switch back at the touch of a button. The ability to roast at lower temperatures also virtually eliminates any risk of bean-surface defects like scorching or tipping.
Insights from an Expert: Christopher Feran’s experience with the Ultra
Pictured: Christopher Feran, a renowned roasting consultant and owner of Aviary coffee roastery
Christopher Feran, a renowned roasting consultant and owner of Aviary coffee roastery, has been trialing the Ultra for us for the past few months and tells us he has been very impressed with the results.
“I really liked my roasts before on the L100 Plus. I spent ages dialing that machine. So my goal was to replicate those profiles, as quickly as possible,” he says. “Using my new counterflow profile, the roasts are less 'roasty' but otherwise taste identical.”
“Because of the efficiency of heat transfer, I'm able to use significantly lower inlet temperatures—reducing energy usage by 20-30%, increasing theoretical batch size, and reducing defects. I don't have any problems with scorching or tipping using the counterflow approach. It's just brilliant,” he adds.
While counterflow mode is the change that has made the biggest impact, Christopher also noted that the upgraded sensor setup has helped his roasting workflow enormously.
“Because of the new probe locations, I'm able to get incredibly reliable BT data using a 50 g sample in counterflow mode and around 80 g in 'classic' mode.” This improvement means that BT-IT profiles are now viable for smaller batch sizes on the Ultra, he points out; on the L100 Plus, he found they worked best for batches of 125 g and above.
“The placement of the exhaust probe also means I now have a more realistic picture of the temperature of the air as it's exiting the roaster,” he adds.
He also praised the new drum pressure sensor, which we introduced partly as a response to his feedback on the L100 Plus. He describes the pressure sensor as “much more consistent and reliable” than his previous method of measuring the pressure at the trier hole. “Because of this, I'm able to dial in my profiles and iterate more rapidly,” he says.
From sample roasting to profile development
Christopher also points out that using the pressure sensor to control airflow makes it much easier to adapt his profiles to different batch sizes. Thanks to this, he hopes to be able to apply this approach to developing profiles on the P3000, ROEST’s production roaster, in the future.
In Counterflow mode, the Ultra’s roast dynamics are much closer to ROEST’s production machine, the P3000. This will greatly simplify the development of modeling and AI tools to help transfer profiles, model roast behavior, and seamlessly scale profiles between machines.
If you plan to use the P3000 as your main production roaster, the Ultra will become an indispensable tool for assessing green coffee behavior during roasting and developing production profiles for the P3000.
What’s next for the world’s best sample roaster?
The enhanced hardware in the L100 Ultra also lays the foundation for future software upgrades, which can be delivered seamlessly over-the-air. We are already planning new features such as advanced airflow control, second crack detection, and more—all part of ROEST’s commitment to continuous innovation.
What if I already have the L100 Plus?
Whenever we design new features, we aim to make it possible to upgrade your machine rather than replace it. For example, features such as the inlet temperature sensor and first crack detection were specifically designed to be retrofittable to existing machines, making ROEST both a cost-effective and sustainable choice.
However, due to the physical differences in the drum between the Ultra and the L100 Plus, it's not possible to upgrade your L100 Plus to an L100 Ultra on your own.
However, we are actively developing a trade-in and upgrade program specifically for existing customers who wish to move up to the Ultra. We'll be releasing more information about this program in the coming months, so stay tuned!
A new standard in sample roasting
The L100 Plus set the benchmark for precision, consistency, and ease of use in sample roasting. The L100 Ultra, however, represents a significant leap forward in sample roasting technology.
For users who want the classic ROEST experience, the L100 Plus remains an exceptional machine. However, the advanced features of the Ultra mean it delivers unparalleled control, speed, and versatility.
Whether you're aiming for rapid sample processing, the delicate development of nuanced flavors, or to develop production profiles to match just about any kind of roaster, the L100 Ultra provides the tools you need to push the boundaries of what sample roasting can be.
As ROEST continues to innovate with future software upgrades, the L100 Ultra is not just an upgrade, but an investment in the future of precision sample roasting.
Learn more about the L100 Ultra feature and technical specificiation here.
Got a question or interested in purchasing the L100 Ultra? Get in touch today via the form below.
